Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Comparative evolution”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 253 records · Page 14Linked to original sources
PubMed1987

AIDS in Europe: current trends and short-term predictions estimated from surveillance data, January 1981-June 1986.

European AIDS surveillance data, reported to the World Health Organization (WHO) Collaborating Centre on AIDS, Paris by 30 June 1986, have been analysed statistically to assess current trends and to provide short-term predictions. Reported case numbers were first adjusted to allow for the estimated time delays between diagnosis and reporting. The adjusted data (cases per half-year of diagnosis) were then fitted using exponential functions over selected time intervals to monitor and compare the evolution of the epidemic in individual countries and in the European Community (EC) as a whole. Predictions to mid-1988 were made by extrapolation. Results are presented for the EC and for the following individual countries: Belgium, Denmark, France, Federal Republic of Germany, Italy, The Netherlands, Spain, Sweden, Switzerland and the United Kingdom.

Acquired Immunodeficiency Syndrome↗
PubMed1987

Nephropathic cystinosis: effect of long-term cysteamine therapy.

Three children with nephropathic cystinosis received cysteamine therapy, mostly in the form of phosphocysteamine, for more than six years. The patients were between two and three years of age at the start of the study. The daily dose of cysteamine was 60 mg/kg as cysteamine base. In all three, rapidly progressive renal failure occurred before their 10th birthday. When comparing their evolution with data on the natural history of childhood cystinosis, no improvement was observed in terms of growth and glomerular function. It is concluded that cysteamine therapy did not provide clear benefit to the three patients reported here.

Body Height↗
PubMed1979

[Alkaline phosphatase activity of the bursa of Fabricius: histochemical study in the normal embryo and during allograft reactions].

Alkaline phosphatase activity allows a certain discrimination between lympho-inhibition following a direct action on the lymphoid stem cells or a modification of mesenchyme/epithelium interactions; in this study we have compared the evolution of this activity in untreated chick embryos and in chick embryos following graft-versus-host-reactions. The important decrease of mesenchyme alkaline phosphatase activity induced here, involves a localisation of allograft reaction in this tissue; this result does not agree with the former explanations about a direct action on the lymphoid stem cells.

Alkaline Phosphatase↗
PubMed1979

[Behaviour of asbestos fibres in the respiratory system as revealed by animal experiments (author's transl)].

By comparing the evolution of chrysotile and amosite fibres in rat lungs, more rapid clearance was found in the case of chrysotile. The rate of chrysotile clearance is strongly influenced by the size factor. The two varieties of asbestos also differ in their chemical behaviour in the lung. The evolution of chrysotile fibers in vivo is characterized by progressive decrease in magnesium content, while silicium retained in the fibre skeleton is practically not eliminated. Transport of fibers from the lungs to the lymph-nodes, the parietal pleura and the diaphragm also differs with the two asbestos varieties. From fibre counts with the electron microscope, chrysotile was more rapidly eliminated from the lungs than amosite. The concentration is higher with amosite in the lymph-nodes, and with chrysotile in the diaphragm. This last result confirms observations made on human lungs.

Animals↗
PubMed1982

[Process of mandibular ossification in mice and evolutionary morphology (experimental study by means of vital staining)].

The injection in vivo of red alizarin S. in young mice during the post-natal period, enabled to show the mechanisms that were modeling the mandible during its development (by apposition-resorption). So it was possible to study : the processes of ossification involved in the eruption of the teeth, the modifications of the bony relief and the alterations of the mandibular angle. It has been attempted to find the links between these phenomena and muscular excitation, function and behaviour. The study of the osseous - muscular - mandibular anatomical set provided a good example of the principle described in Evolutionary morphology: "The comparatively free evolution of the elements in the anatomical set that they constitute (Sakka, 1973)."

Animals↗
PubMed1980

[Cerclage and infection. Clinical and therapeutic study (author's transl)].

The authors compared the evolution of the pregnancy, of the labour and of the post-partum period in 75 patients who had cerclage for cervico-isthmial incompetence and in 68 mothers who had no pathology in the cervix (the control group). A state of infection developed more often in the mother and in the fetus and/or the newborn in the group that had cerclage than in the control group. The perinatal death of 7 infants in the group that had cerclage, of which 5 were due to infection, is to be deplored. The only perinatal death in the control group was due to an infection.

Adult↗
PubMed1976

Cyclophosphamide (CP) substituting azathioprine after renal transplantation.

Eighteen patients received CP substituting AZ after renal transplantation following evidence of hepatitis. We have compared graft evolution before and after treatment with CP. Twelve patients showed no modification in graft evolution. In four patients the renal function decreased but it did not seem attributable to the change of the drug. Two patients showed intolerance attributable to the change of the drug. In one patient who received CP instead of AZ since the data of the transplant onwards, with no evidence of hepatic lesion, renal function decreased but this did not seem attributable to the use of the drug. The dose of CP in renal transplantation is discussed. We conclude that CP is a good substitute for AZ in renal transplanted patients. Adequate doses seemed to range between 0.7 and 1 mg/kg/day.

Azathioprine↗
PubMedDate not supplied

[Results of a school addictive substances abuse prevention program: the Barcelona PASE pilot project].

A pilot project for the prevention of substance abuse in schools (PASE) has been developed in 1988-90 in sixth and seventh grades (12-14 years-old) in 11 primary schools in the city of Barcelona (Spain). Data on consumption smoking, alcohol and drugs were obtained before the implementation of the project, shortly afterwards, and in the next school year. These results are presented, comparing the evolution of attitudes, beliefs and behavior of these school children with a control group composed of students from reference schools. The results suggest a modest but significant effect of the program, which seems to decrease over time for smoking, suggesting the need for booster interventions to maintain its effects.

Adolescent↗
PubMed1993

The effects of ventilation tube placement on hearing, speech, language, cognition and behaviour.

As a part of a larger, multidimensional study on secretory otitis media (SOM) and its relation to children's development, the effects of ventilation tube (VT) placement on hearing, speech, language, cognition and behaviour were studied over a six month period. Children with a clear and persistent picture of SOM were examined just before tubes were inserted and again, with the same measures, six months later. Their evolution was compared to that of a control group. The results indicate, as was expected, that the hearing of the children with SOM normalized very quickly after surgery. Speech and expressive language functions were comparable for both groups at the two moments of examination. Only verbal comprehension of the SOM-group was found to be slightly improved in the course of a six month period. No differences in general cognitive functioning and in behaviour were found between both groups.

Child Behavior↗
PubMed1997

Molecular phylogenetics of bacterial endosymbionts and their vestimentiferan hosts.

Vestimentiferan tube worms from deep-sea hydrothermal vents and cold-water seeps rely entirely on sulfur-oxidizing bacterial endosymbionts for nutriment. We examined host-symbiont co-evolution by comparing phylogenetic trees from symbiont 16S ribosomal DNA and host mitochondrial COI genes. The endosymbionts comprised two distinct clades, one associated with tube worms from basaltic vent habitats and the other associated with tube worms from sedimented seep-like environments. Within each symbiont clade, 16S rDNA sequences were nearly identical, suggesting that vent vestimentiferans share a single endosymbiont species that is distinct from the seep endosymbiont species. A third endosymbiont type, related to the seep species, was found in a tube worm collected from a whale carcass. Our results are consistent with a horizontal model of symbiont transmission.

Animals↗
PubMed1997

[Our experience in portal cavernomatosis in childhood: cross-sectional study and analysis of results].

A retrospective and transversal study of our patients with portal cavernomatosis is developed, with the aim of comparing the evolution and the present status of the patients that have undergone different therapeutical approaches. Between 1975 and 1995, 15 patients with portal cavernomatosis have been treated. Personal history, signs and symptoms at the moment of diagnosis, and treatment were analyzed. Now, the controls have been made by physical examination and ECO-Doppler of the espleno-portal system. In 6 cases the absence of bleeding made surgery unnecessary. In the 9 patients with digestive haemorrhage, it could be controlled pharmacologically, with a later surgical approach. Now, all non-operated and 6 operated patients show splenomegaly, without bleeding. The ECO-Doppler shows colateral flow, the splenomegaly in the non-operated and the surgical shunts and the hepatofugal circulation in the operated patients. Looking at our results, we believe that prophylactic surgery is not indicated. In those cases of digestive bleeding, surgery after the complete resolution of the acute disease shows good results at a short and long term.

Child, Preschool↗
PubMed1998

Trends in childhood cancer mortality as indicators of the quality of medical care in the developed world.

BACKGROUND: Mortality from childhood cancer in general and childhood leukemia in particular has sharply declined in economically developed countries over the last 30 years, whereas the incidence of these diseases has remained essentially unaltered. Therefore, childhood malignancies can be used as tracers of accessibility to and effectiveness of medical care. The objective of this study was to compare the reduction of mortality from childhood cancer in general, and childhood leukemia in particular, in four economically developed areas of the world, to assess accessibility to and effectiveness of technologically advanced medical care. METHODS: The authors used data from the World Health Organization to compare the evolution over time of gender specific, age-adjusted mortality from childhood cancer in general and childhood leukemia in particular in the childhood (birth to age 14 years) populations of North America, western Europe, Japan, and Australia and New Zealand during the period 1960-1993. They assessed the evolution over time and the cumulative percentage representing the decline in mortality from childhood cancer and childhood leukemia in the four aforementioned areas of the world. RESULTS: The decline in mortality from both the disease entities considered and for both genders has been more pronounced in North America than in other economically developed areas of the world. CONCLUSIONS: When disease control depends on technologically advanced medical care, as in the case of cancer, the North American population is benefited by earlier and effective introduction of new therapeutic approaches. This conclusion does not apply to other childhood diseases, the incidence of which is higher among low-income groups and control of which depends on prevention rather than treatment.

Adolescent↗
PubMed1985

Histones in protistan evolution.

The potential of comparative studies on histones for use in protistan evolution is discussed, using algal histones as specific examples. A basic premise for the importance of histones in protistan evolution is the observation that these proteins are completely absent in prokaryotes (and cytoplasmic organelles), but with few exceptions, the same five major histone types are found in all higher plants and animals. Since the histone content of the algae and other protists is not constant, some of these organisms may represent transition forms between the prokaryotic and eukaryotic modes of packaging the genetic material. Comparative studies of protistan histones may thus be of help in determining evolutionary relationships. However, several problems are encounter with protistan histones, including difficulties in isolating nuclei, proteolytic degradation, anomalous gel migration of histones, and difficulties in histone identification. Because of the above problems, and the observed variability in protistan histones, it is suggested that several criteria be employed for histone identification in protists.

Animals↗