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PubMed1997

Genomic diversity and evolution of papillomaviruses in rhesus monkeys.

We are studying the diversity of and relationships among papillomaviruses (PVs) to understand the modes and timescales of PV evolution and in the hope of finding animal PVs that may serve as model systems for disease caused by human PVs (HPVs). Toward this goal, we have examined 326 genital samples from rhesus monkeys and long-tailed macaques with a PCR protocol optimized for detecting genital HPV types. In 28 of the rhesus monkey samples, we found amplicons derived from 12 different and novel PV genomes, RhPV-a to RhPV-m, with the likely taxonomic status of "type." The frequency with which novel RhPVs were detected suggests that rhesus monkeys may play host to PVs with a diversity similar to that of humans. In phylogenetic trees, all 12 of the different RhPVs and the previously described type RhPV-1 were members of the genital HPV supergroup and formed three minor branches distinct from the 11 branches formed by genital HPVs. We also identified a novel PV amplicon, MfPV-a, from a long-tailed macaque, a species belonging to the same genus as rhesus monkeys. MfPV-a turned out to be a close relative of five RhPVs. It appears that the evolution of primate lineages leading to the genus Macaca and to humans created transmission barriers for PVs, resulting in viral evolution closely linked to the host. Additional support for the linked-evolution hypothesis comes from considering the phylogenetic association of two other ape and monkey PVs with the genital HPVs, the supergroup formed by at least seven ungulate PVs, and the isolated phylogenetic position of the only known bird PV.

Amino Acid Sequence↗
PubMed2003

[Evolution of the treatment of pancreatic cancer].

Cancer of the pancreas was not diagnosed until the nineteenth century, and the first surgical attempts were not carried out until the end of that century, and then only within the framework of local tumour removal. Already in 1898, however, Codivilla described the operative method that is today considered the standard operation and which, in the form of partial duodenopancreatectomy, is the most commonly performed procedure on the pancreas. Evolutionary change in this area represents nothing more than the gradual introduction of minor modifications which, however, had no impact on the " heart" of the surgical approach. The particular feature of surgical treatment of pancreatic cancer--since 1935 known as Whipple's procedure--is the considerable length of time of 80 years that it took before it finally found widespread acceptance. Further several decades passed until, by the end of the 20th century, recognizable successes were reported, for example, a resection rate of 30%, a hospital mortality rate of less than 5% in specialized centers, and a reported 5-year survival rate varying from 1% to 20%. Even after the last 100 years of slow evolution, surgeons have by no means conquered cancer of the pancreas, and the low 5-year survival rates, together with the recurrences and late metastases prompted Trede in the year 2002 to remark: "we have to conclude that surgery alone cannot cure pancreatic carcinoma".

History, 16th Century↗
PubMed2006

Positive and negative selection in the beta-esterase gene cluster of the Drosophila melanogaster subgroup.

We examine the pattern of molecular evolution of the beta-esterase gene cluster, including the Est-6 and psiEst-6 genes, in eight species of the Drosophila melanogaster subgroup. Using maximum likelihood estimates of nonsynonymous/synonymous rate ratios, we show that the majority of Est-6 sites evolves under strong (48% of sites) or moderate (50% of sites) negative selection and a minority of sites (1.5%) is under significant positive selection. Est-6 sites likely to be under positive selection are associated with increased intraspecific variability. One positively selected site is responsible for the EST-6 F/S allozyme polymorphism; the same site is responsible for the EST-6 functional divergence between species of the melanogaster subgroup. For psiEst-6 83.7% sites evolve under negative selection, 16% sites evolve neutrally, and 0.3% sites are under positive selection. The positively selected sites of psiEst-6 are located at the beginning and at the end of the gene, where there is reduced divergence between D. melanogaster and D. simulans; these regions of psiEst-6 could be involved in regulation or some other function. Branch-site-specific analysis shows that the evolution of the melanogaster subgroup underwent episodic positive selection. Collating the present data with previous results for the beta-esterase genes, we propose that positive and negative selection are involved in a complex relationship that may be typical of the divergence of duplicate genes as one or both duplicates evolve a new function.

Animals↗
PubMed2003

The intermetatarsal articular facet of the first metatarsal bone in humans: a derived trait unique within primates.

The occurrence and morphology of an intermetatarsal facet of the first metatarsal bone have been investigated in a series of 306 nonhuman primates representative of 40 genera, and in a series of 412 human metatarsal bones (dried bones) (215 left, 197 right). In nonhuman primates, no case of intermetatarsal facet was observed in the 306 first metatarsal bones studied. In humans, a well-defined intermetatarsal facet was observed in 127 out of the 412 bones (30.8%); no significant difference was observed between the left and right sides. The shape of the facet was elliptical, more or less elongated; it had a mean major axis (height) of 10.7 mm, and a mean minor axis (width) of 6.1 mm (extremes: 5 x 3 mm and 17 x 10 mm). The facet was located in the dorsal third of the lateral side of the first metatarsal in 103 out of 127 cases (81.1%), and in the middle third in 24 out of 127 cases (18.9%); it was never observed in the plantar third. The intermetatarsal facet was in connection with the proximal articular facet for the medial cuneiform in 68 out of 127 cases (53.5%), and it was separated from the proximal facet by a small nonarticular area or groove in 59 out of 127 cases (46.5%). The present observations suggest that the human first intermetatarsal facet is a derived trait unique within primates (autapomorphy) which is present in approximately one third of individuals. The appearance of this new articular facet in human evolution seems clearly related to the morphological modifications of the foot due to the acquisition of bipedalism, and more particularly to the loss of abductability of the hallux and its permanent adduction.

Animals↗
PubMed1999

Human immunodeficiency virus type 1 genetic evolution in patients with prolonged suppression of plasma viremia.

Treatment of human immunodeficiency virus type 1 (HIV-1)-infected patients with combination drug regimens results in a reduction of plasma viral load to levels below the limit of detection. To investigate the genomic fluctuations in HIV-1 populations from long-term responders to antiviral therapies we analyzed the viral sequence evolution of env and pol genes from sequential peripheral blood mononuclear cell (PBMC) DNA samples of three infected patients. Analyses of sequences covering the V3 and flanking env regions obtained from blood samples at the beginning of the therapy and at 14 or 24 months from baseline revealed that HIV-1 quasispecies continue to evolve in the three patients following combination antiretroviral therapy. Minor drug-resistant mutant subpopulations were also searched for and found in one patient. Interestingly, no minor resistant subpopulations were found in the other two patients despite the fact that they showed evidence of ongoing viral replication. Finally, the genetic analysis of the env gene shows a reduction in PBMC env viral population diversity after long-term response to the therapy in all the patients analyzed.

Anti-HIV Agents↗
PubMed2005

[Chronic pancreatitis--pancreas cancer: influence of genetic factors].

Chronic pancreatitis: Only recently mutations in several genes were found in patients with chronic pancreatitis. In those with a familial chronic pancreatitis mutations of the cationic trypsinogen were identified and the variants N29I and R122H lead to an autosomal dominant disease. In this group of patients the mutation N34S of the trypsin inhibitor SPINK1 was detected. In so-called idiopathic pancreatitis both variants of the SPINK1 and of the CFTR (cystic fibrosis transmembrane conductance regular) were identified. Alterations in both genes were also found in patients with alcoholic chronic pancreatitis. The strongest risk factor for chronic pancreatitis were trypsinogen mutations N29I and R122H mutations. However, both SPINK1 and CFTR increased the risk for chronic pancreatitis to a higher level than alcohol consumption. A genetic investigation should be performed in familial disease and younger age, but also in patients without family history and higher age a mutation could be found. Pancreas cancer: In 10% of the patients with pancreas cancer other members of the family were affected from the disease. Some of them belong to well characterized familial syndroms like HNPCC or Peutz-Jeghers-syndrom. In a minority of the others a genetic factor may be found, too. In sporadic disease the development of the tumor is characterized by continued acquirement of genetic alterations described by the PanIN model (pancreatic intraepithelial neoplesia). This means that the evolution of the neoplasia progresses from normal tissue via epithelial hyperplasy (PanIN 1A), papillary hyperplasy without (PanIN 1B) and with dysplasy (PanIN 2) and carcinoma in situ (PanIN 3) to invasive pancreas cancer. The progression is associated with genetic alterations of the cells (mutations of ki-ras, p16, p53 etc.). This results in deterioration of control of the cell cycle and the apoptosis and explains the malignancy of the disease. These findings may be used in the future to develop newer therapeutic principles in order to improve the dismal prognosis of this disease.

Carrier Proteins↗
PubMed2005

Clusters of mutations from transient hypermutability.

Collections of mutants usually contain more mutants bearing multiple mutations than expected from the mutant frequency and a random distribution of mutations. This excess is seen in a variety of organisms and also after DNA synthesis in vitro. The excess is unlikely to originate in mutator mutants but rather from transient hypermutability resulting from a perturbation of one of the many transactions that maintain genetic fidelity. The multiple mutations are sometimes clustered and sometimes randomly distributed. We model some spectra as populations comprising a majority with a low mutation frequency and a minority with a high mutation frequency. In the case of mutants produced in vitro by a bacteriophage RB69 mutator DNA polymerase, mutants with two mutations are in approximately 10-fold excess and mutants with three mutations are in even greater excess. However, phenotypically undetectable mutations seen only as hitchhikers with detectable mutations are approximately 5-fold more frequent than mutants bearing detectable mutations, indicating that they arose in a subpopulation with a higher mutation frequency. Excess multiple mutations may contribute critically to carcinogenesis and to adaptive mutation, including the adaptations of pathogens as they move from host to host. In the case of the rapidly mutating riboviruses, the viral population appears to be composed of a majority with a mutation frequency substantially lower than the average and a minority with a huge mutational load.

Animals↗
PubMed2004

Evolutionary dynamics and the phase structure of the minority game.

We show that a simple evolutionary scheme, when applied to the minority game (MG), changes the phase structure of the game. In this scheme each agent evolves individually whenever his wealth reaches the specified bankruptcy level, in contrast to the evolutionary schemes used in the previous works. We show that evolution greatly suppresses herding behavior, and it leads to better overall performance of the agents. Similar to the standard nonevolutionary MG, the dependence of the standard deviation sigma on the number of agents N and the memory length m can be characterized by a universal curve. We suggest a crowd-anticrowd theory for understanding the effect of evolution in the MG.

Biological Evolution↗
PubMedDate not supplied

[Situation of the epidemic strain C:2b:P1.2,5 of Neisseria meningitidis after A+C vaccination].

Following the use of an extensive immunisation campaign targeting the population between ages 2 and 19 in the majority of the Autonomous Communities (Regions), for the purpose of controlling the "outbreak or epidemic wave" caused by serogroup C in 1996-97, there was great interest in ascertaining the situation of the well-known epidemic strain C:2b:P1.2.5, which had been identified as the cause of the changes brought about in the epidemiological profile of meningococcal disease in Spain, as this would enable us to analyse some of the possible future tendencies of this disease in our country. An analysis of the situation in the first 10 months of 1999 reveals that we have reverted to figures similar to those which, both insofar as the number of cases as well as the frequency of serogroups, were observed in Spain at the beginning of the decade of the nineties, although the epidemic strain C:2b:P1.2.5 represents 56% of the total cases of serogroup C. The strains of serotype 2a, very frequent in serogroup C in European countries, continue to represent a minority in Spain. Finally, it is of interest to mention the appearance of antigen variants which could be the result of processes of intra-specific genetic recombination and which would presumably have been selected in terms of their evolutive advantages.

Adolescent↗
PubMed2002

[Analysis for therapy and prognosis of undifferentiated carcinoma with lymphoid stroma in salivary gland].

OBJECTIVE: To analyse the clinical characteristic, evolution and prognosis of undifferentiated carcinoma with lymphoid stroma(malignant lymphoepithelial lesions, MLEL) in salivary gland. METHODS: During 1989 and 1997, 21 cases of MLEL in salivary gland were treated. The primary site was parotid in 18 cases, palate minor salivary gland in 2 cases and submandibular gland in 1 case. There were 5 men and 16 women with an age range of 31 to 74 years (median, 41 years). For stage II, III, mass dissection and superficial or total parotidectomy were adopted. The facial nerve was preserved when it had not been invaded. 3 to 25 lymph nodes were subjected to exam in pathology for every neck dissection specimen. For stage IV, neck dissection may be included, when necessary. All patients were irradiated on primary site or including ipsilateral neck 2 to 9 weeks after operation, except 2 cases irradiated after recurrence. Tumor doses were 52.03Gy in average. RESULTS: There were 3/21 patients with recurrent benign lymphoepithelial lesion history (BLEL). The shortest duration from the recurrence to specific diagnosis was 6 months, and the longest was 2 years. The II, III, IV stage cases were 8(42.9%), 3 (14.3%), 10 (47.6%), respectively. All of II, III stage cases were N0. The cases with positive lymph nodes were 10/21(47.61%). The 5-year survival rate was 70.66%, for II, III, IV stage was 86.68%, 66.67%, 33.3%, respectively, analyzed by Life Table. And test with Wilcoxon (Gehan) statistic, P=0.2789, means there was no specific difference among each group. In the group, 5 patients dead and 2 lost follow up (counted in dead); mortality was 33.31%, all of them were IV stage. Superior and middle deep cervical metastasis were found in 4 of those patients with parotid MLEL, and neck dissection and ipsilateral neck irradiation were adopted. Recurrence was found in 7/21(33.3%), 5 of 7 cases were IV with N2 or N3, 2 of 7 were palate MELE in early or middle stage. There were 6/7 recurrence occurred on neck. The duration from first treatment to recurrence was 20.7m in median, the shortest was 5 months and the longest was 65 months, among them the recurrence occurred shorter than 20 months in 5 cases. After comprehensive treatment, 3 patients were alive and 3 cases dead. Metastasis occurred in 4 patients in IV stage (T4N2M0), with positive middle cervical lymph nodes in 3 cases treated by neck dissection before. CONCLUSION: Recurrent BLEL intends to develop to malignant lesion. Superior and middle deep cervical lymph nodes metastasis were not unusual in IV stage patients. Neck, dissection and irradiation should be carried out on these patients, especially for those with N2. The peak time of recurrence was 2 years after the first treatment, and during the time, the tumor proliferated rapidly. Active comprehensive treatment should be carried out on recurrent patients. For patients with positive middle deep cervical lymph nodes, chemotherapy or other methods should be adopted to prevent distant metastasis.

English Abstract↗
PubMedDate not supplied

[Idiopathic intervertebral disc calcification in children: the role of diagnostic imaging. A case report].

The idiopathic calcification of the intervertebral disc in childhood is a rare syndrome with unknown aetiology. This pathology is more frequent in males, with predominant localization to cervical spine. The natural evolution of the syndrome is the progressive and spontaneous resorption of the calcific deposit, with symptom regression. We report a case of an acute and worsening torticollis in a 10-year-old child, with reference to a recent minor cervical distortion, resistant to analgesic treatment. X-ray evaluation, executed after a week from the appearance of torticollis, showed an oval calcification in the nucleus pulposus of the C6-C7 intervertebral disc. The CT and especially the MRI concurred to recognize a disc hernia and an adjacent osteo-ligamentous pathologic participation. In particular, MRI showed the adjacent vertebral spongy bone edema and the active enthesiopathy of the posterior longitudinal ligament.

Calcinosis↗
PubMed1990

Biculturality and homosexuality.

In an effort to sensitize service providers to bicultural socialization, a small but growing literature has surfaced in which theories are proposed explaining the socialization process, cultural identification, and evolution of self-concept for those functioning in two cultures. In this article, the authors examine the extent to which previously developed explanatory theories of cultural and ethnic identity and bicultural socialization apply to the experience of sexual minorities, and offer a conceptual framework for adequately assessing the experience of homosexual clientele. The multifaceted nature of the practitioner's role is discussed, and gender-sensitive practice methods are given that may assist sexual minorities in developing optimum functioning.

Acculturation↗
PubMed1984

[Genetic polymorphism of transferrins in Bovinae].

Variability of transferrins in Bovinae is controlled by two loci: Tf (the locus of structural transferrin gene) and T (the locus of a gene responsible for protein modification). Originally, the ancestors of Bovinae, like the other ruminants, had the R type of transferrin (T-/T- genotype, inactive T gene). Later on, the T gene activation occurred and the B type appeared (T+/T-, T+/T+ genotypes). The subsequent evolution of Bovinae was accompanied by almost complete fixation of T+ allele. In one of the Bovinae representatives (Bos taurus L.) the frequency of T- allele remained at the level of approx 0.1. A hypothesis is proposed which explains the change of the transferrin type in Bovinae by imitation of multiple allelic forms of this protein present in Tf heterozygotes, by supplementary modificatory multiple transferrin forms arising on activation of the minor gene (T+). This process is assumed to involve the reduction of Tf locus variability. Since this hypothesis proceeds from the assumption of TF heterozygote advantage, the question is considered, whether this assumption is compatible with high polymorphism of Tf locus which significantly exceeds that for other loci.

Alleles↗
PubMed2004

Habitat-specific pigmentation in a freshwater isopod: adaptive evolution over a small spatiotemporal scale.

Pigmentation in the freshwater isopod Asellus aquaticus (Crustacea) differed between habitats in two Swedish lakes. In both lakes, isopods had lighter pigmentation in stands of submerged vegetation, consisting of stoneworts (Chara spp.), than in nearby stands of reed (Phragmites australis). Experimental crossings of light and dark isopods in a common environment showed that pigmentation had a genetic basis and that genetic variance was additive. Environmental effects of diet or chromatophore adjustment to the background had minor influence on pigmentation, as shown by laboratory rearing of isopods on stonewort or reed substrates, as well as analyses of stable isotope ratios for isopods collected in the field. In both study lakes, the average phenotype became lighter with time (across generations) in recently established stonewort stands. Taken together, these results indicate that altered phenotype pigmentation result from evolutionary responses to local differences in natural selection. Based on the assumption of two generations per year, the evolutionary rate of change in pigmentation was 0.08 standard deviations per generation (haldanes) over 20 generations in one lake and 0.22 haldanes over two generations in the other lake. This genetic change occurred during an episode of population growth in a novel habitat, a situation known to promote adaptive evolution. In addition, stonewort stands constitute large and persistent patches, characteristics that tend to preserve local adaptations produced by natural selection. Results from studies on selective forces behind the adaptive divergence suggest that selective predation from visually oriented predators is a possible selective agent. We found no indications of phenotype-specific movements between habitats. Mating within stonewort stands was random with respect to pigmentation, but on a whole-lake scale it is likely that mating is assortative, as a result of local differences in phenotype distribution.

Adaptation, Physiological↗
PubMed1999

Evolution of CT findings in patients with cystic fibrosis.

OBJECTIVE: The aim of our study was to assess the evolution of pulmonary CT findings in cystic fibrosis patients. MATERIALS AND METHODS: Serial CT examinations were performed in four different follow-up periods on 107 patients with cystic fibrosis. Lung images of the initial and follow-up CT were reviewed and scored for specific morphologic findings. CT findings were correlated with the results of the pulmonary function tests and clinical (Shwachman-Kulczycki) scores. RESULTS: Morphologic changes were minor within the first 18 months of follow-up compared with the period after 18 months. The increase of the overall score was significantly higher in groups with follow-up periods longer than 18 months compared with groups with follow-up periods shorter than 18 months. Various components of morphologic changes contributed to the sequential changes seen on the CT scans. All morphologic changes and the CT scores correlated significantly (p < .0001) with pulmonary function tests and clinical score. CONCLUSION. Serial CT scans allow assessment of the evolution of pulmonary abnormalities in patients with cystic fibrosis. CT seems to have advantages over pulmonary function tests and clinical scoring in the depiction of pulmonary changes over time.

Adolescent↗
PubMedDate not supplied

Conservation and divergence of Bmp2a, Bmp2b, and Bmp4 expression patterns within and between dentitions of teleost fishes.

The diversity of tooth location in teleost fishes provides an excellent system for comparing genetic divergence between teeth in different species (phylogenetic homologs) with divergence between teeth within one species (iterative homologs). We have chosen to examine the expression of three members of the bone morphogenetic protein (Bmp) family because they are known to play multiple roles in tooth development and evolution in tetrapod vertebrates. We characterized expression of Bmp2a, Bmp2b, and Bmp4 during the development of oral and pharyngeal dentitions in three species of teleost fishes, the zebrafish (Danio rerio), Mexican tetra (Astyanax mexicanus), and Japanese medaka (Oryzias latipes). We found that expression in teleosts is generally highly conserved, with minor differences found among both iteratively homologous and phylogenetically homologous teeth. Expression of orthologous genes differs in several ways between the teeth of teleost fishes and those of the mouse, but between these vertebrate groups the summed expression pattern of Bmp genes is highly conserved. Significantly, the toothless oral region of the zebrafish lacks Bmp expression domains found in teleosts with oral teeth, implicating these genes in evolutionary tooth loss. We conclude that Bmp expression has been largely conserved in vertebrate tooth development over evolutionary time, and that loss of Bmp expression is correlated with region-specific loss of the dentition in a major group of fishes.

Animals↗