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PubMed2003

Molecular phylogenetics employing modern and ancient DNA.

Comparative studies of DNA in recent populations and characterisation of ancient hereditary material have contributed very interesting facts to our understanding of evolution of modern mankind. Analysis of DNA homology in related species, assessment of mutations and polymorphisms in various populations and new DNA sequence data from prehistoric finds allowed - via sophisticated DNA extraction techniques, PCR, sequencing and digitalised processing of genetic information - insights into possible roots of Homo sapiens and related species, migration patterns and ancient cultural habits, thus enrhing the palaeoanthropological discipline. However, a presentation of this development would not be complete without pointing towards the methodological limitations and manifold presentations burdened with artifacts, data misinterpretation and unjustified conclusions. Presently, this modern field of research is in its consolidation phase and new parameters for quality control and authentication are being implemented to avoid spectacular but unfounded reports. It is expected that most of the problems connected to old biomolecules may be closely related to fossilisation parameters. The future challenge will be the full understanding of the complex and multi-faceted processes underlying diagenesis, including the elucidation of nucleic acid postmortem damage".

Amino Acid Motifs↗
PubMed2003

[In vitro evaluation of allergenicity of dried food powders manufactured for food provocation test].

Food provocation test (FPT) is one of important diagnostic methods for food allergy, but no standard antigens for FPT have yet been developed. In this study, dried powders were manufactured from five kinds of foods (cow's milk, hen egg, chicken, soybean and wheat) by spray-drying or freeze-drying and examined in vitro for their usefulness as antigens for FPT. In SDS-PAGE, the migration pattern of the extract from each powder was the same as or closely similar to that of the extract from its material. When analyzed by ELISA, a good correlation (r=0.853-0.978) in the reactivity with sera from food-allergic patients was observed between the extracts from each powder and its material. Moreover, in cow's milk, hen egg and soybean, almost the same ELISA inhibition curves were drawn, regardless of whether the extracts from each powder and its material were used as immobilized antigens or inhibitors. These results demonstrated that each powder contains the same allergens as its material at almost the same levels, being useful as an antigen for FPT. Favorably, the powders were found to be stored without significant changes in IgE reactivity at -20 degrees C or 5 degrees C for more than 18 months, although their storage at room temperature was suggested to be avoided.

Allergens↗
PubMed1992

Alu insertion polymorphism: a new type of marker for human population studies.

A PCR-based method was used to screen 462 individuals from Japan, Papua New Guinea, Indonesia, and Australia for an Alu family insertion polymorphism. The frequency of this Alu insertion shows significant heterogeneity among island subgroups of the Indonesian sample and between the Japanese-Indonesian populations and the Australian-New Guinean populations. The simple, rapid PCR-based screening technique and the significant frequency differences among populations demonstrate that Alu insertion polymorphisms are potentially valuable markers for studies of the evolutionary history and migration patterns of modern humans.

Australia↗
PubMedDate not supplied

Structural proteins of classic and variant strains of infectious bursal disease viruses.

Structural polypeptides of six tissue-culture-origin (BGM-70 continuous cell line) infectious bursal disease viruses representing classic and variant strains of serotype 1 and one serotype 2 strain were analyzed and compared by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Additionally, two of the variant strains were propagated in vivo in bursa of Fabricius and compared with those grown in cell culture. Differences among the structural proteins of serotype 1 viruses were minor and probably of no value in differentiating these viruses. However, distinct differences were observed between serotype 1 and 2 viruses. The bursa-derived viruses were different from those propagated in cell culture in molecular weights and in proportions of the proteins. The bursa-derived strains had protein migration patterns similar to those described for tissue-culture-incomplete virus particles.

Infectious bursal disease virus↗
PubMed1992

Detection of heterozygous mutations in the RB1 gene in retinoblastoma patients using single-strand conformation polymorphism analysis and polymerase chain reaction sequencing.

Several families segregating the autosomal dominant form of the hereditary retinoblastoma predisposition gene have been analysed for the causative mutation. We have used the single-strand conformation polymorphism (SSCP) technique to screen for mutations, exon by exon, in the RB1 gene in affected patients from these families. The SSCP technique has proved a rapid and simple technique which relies on the sequence-dependent migration of single-stranded DNA in a non-denaturing polyacrylamide gel. Oligonucleotide primers flanking all 27 exons and the promoter region of the RB1 gene are reported here. The polymerase chain reaction (PCR)-amplified products range in size from 212 to 625 bp and include a flanking intron sequence which allows detection of mutations in these regions. The sensitivity of SSCP is optimal when DNA fragments are approximately 200 bp long. Consequently, restriction enzyme sites for each amplified region were identified, reducing the size of the PCR products analysed to less than 250 bp. Bands with aberrant migration patterns were observed on SSCP gels in the lymphocyte DNA from two patients with bilateral, familial retinoblastoma. Sequence analysis of these DNA fragments revealed the causative mutations. These consisted of a 1-bp insertion of a T in the coding strand of exon 20 and a G----A mutation in the coding strand of exon 14. This approach has proved to be a powerful method for the rapid detection of germline mutations in the RB1 gene, a programme which can be extended to individuals with new mutations.

Base Sequence↗
PubMed1992

Immunological functions and in vivo cell-cell interactions of T cells in the spleen.

The spleen is an important lymphoid organ, involved in immune responses against all types of antigen that appear in the circulation. Its complex anatomical organization, with distinct compartments containing specialized cell types, provides a microenvironment which allows different cell-cell interactions and determines the direction of developing immune responses. In this review we evaluate the vast amount of in vitro data dealing with antigen presentation, cell-cell interactions, T and B cell activation, and the immunoregulatory role of cytokines, as suggested to be involved in immune responses. As a basis for understanding of in vivo processes, these in vitro data will be related to discrete phenomena of in vivo immune responses, such as antigen localization/trapping, cell migration patterns of immunocompetent cells, cytokine production, and antibody formation in the different compartments of the spleen. Finally, we try to bring order to the sequence of events that occur in the spleen after antigenic challenge by presenting an in vivo model for T cell dependent and T cell independent immune responses.

Animals↗
PubMed1992

The molecular epidemiology of rotavirus infection in Ga-Rankuwa, southern Africa.

Rotaviruses were detected in 32.8 pc (96/292) of stool specimens collected from infants and young children with gastroenteritis attending the rehydration unit at Ga-Rankuwa Hospital between January and December 1989. A seasonal distribution was observed with an increase in numbers shedding the virus during the colder months of the year. Based on variations in the migration pattern of the RNA genome segments when passed through polyacrylamide gels, seven different RNA electrophoretypes were identified; 82 pc of the patients had virus with long patterns and 17 pc with short patterns. A mixed infection was observed in one case with both a long and a short virus. A single dominant long electrophoretype persisted throughout the 12 month study period, whereas the other minor types co-circulated at varying intervals.

Child, Preschool↗
PubMed1992

High frequency of mutations in exon 10 of the porphobilinogen deaminase gene in patients with a CRIM-positive subtype of acute intermittent porphyria.

Acute intermittent porphyria (AIP) is an autosomal dominant disease characterized by a partial deficiency of porphobilinogen (PBG) deaminase. Different subtypes of the disease have been defined, and more than 10 different mutations have been described. We focused our study on exon 10, since we previously found that three different mutations were located in this exon and that two of them seemed to be relatively common. We used denaturing gradient gel electrophoresis (DGGE) after in vitro amplification to detect all possible mutations in exon 10 in 41 unrelated AIP patients. In about one-fourth of these patients we could distinguish three abnormal migration patterns, indicating the presence of various mutations. Additional sequencing demonstrated the presence of three different single-base substitutions. Two of these mutations had already been described. A third one consisted of a C-to-T transition located at position 499 of the PBG deaminase mRNA and resulted in an Arg-to-Trp substitution. All three mutations were found in patients with cross-reacting immunological material (CRIM)-positive forms of AIP. The high frequency of these mutations make DGGE analysis of exon 10 a useful approach allowing the direct direction of the DNA abnormality in most of the families with the CRIM-positive subtype of AIP.

Acute Disease↗
PubMed2004

Emergence of resistance to carbocyclic oxetanocin G in herpes simplex virus type 1 and genetic analysis of resistant mutants.

AIM: To elucidate the potentiality of emergence of drug-resistance to carbocyclic oxetanocin G (C.OXT-G), a new effective antiviral drug for herpetic keratitis during treatment and the mechanism of this drug resistance. METHODS: A C.OXT-G resistant strain (C.OXT-Gr) was established by serially propagating the herpes simplex virus (HSV) -1 in African green monkey kidney (VERO) cells in the presence of C.OXT-G. After the drug sensitivity assay and the thymidine kinase (TK) activity assay, the molecular basis for the drug resistance was studied using polymerase chain reaction-single strand conformation polymorphism (PCR-SSCP) analysis and PCR direct sequencing technology. RESULTS: After the 10th passage in 10 microm C.OXT-G, the ED50 of the C.OXT-Gr was 17.08-fold greater than that of the original strain on the average and the TK activities of these resistant strains were extremely reduced. PCR-SSCP analysis on TK gene of the wild HSV-1 and the C.OXT-Gr showed altered migration patterns in part 3 and part 4, while PCR-SSCP analysis on DNA polymerase gene showed no difference among the viruses. Sequence analysis revealed a deletion of G at position of 430 that caused frameshift, resulting in premature termination in the TK gene. CONCLUSION: The drug resistance to C.OXT-G may appear during the treatment due to the deficiency of TK activity caused by a single mutation in the TK gene of HSV-1.

Animals↗
PubMedDate not supplied

Cancer in Asian American males: epidemiology, causes, prevention, and early detection.

OBJECTIVES: The objective of this paper is to discuss the epidemiology, etiology, and cultural phenomena that characterize cancers specific to Asian American males. METHODS: The author reviewed various published literature concerning the health of Asian American males. RESULTS: Data show an epidemiological dichotomy in cancer incidences between Asian American males and the general U.S. male population. First, lung and colorectal cancers are among the top three cancers for most Asian groups, similar to the situation in the White population. Second, prostate cancer is the leading, or second leading, cause of cancer for Chinese, Japanese, and Filipino males -- all groups considered, in U.S. terms, to be more established in their migration patterns. Third, liver and stomach cancer are in the top five cancers for most Asian groups, an incidence not shared by the White population. CONCLUSIONS: The most common cancers in Asian American males involve the interplay of host genetic and environmental factors, and both primary and secondary prevention strategies are necessary to decrease the morbidity and mortality rates of this uniquely diverse population.

Asian↗
PubMed1992

Quantitative measurement of lipoprotein surface charge by agarose gel electrophoresis.

The electrophoretic mobilities of low density lipoprotein (LDL) and six pure proteins in a 0.5% agarose gel have been compared to literature electrophoretic mobility values determined by the Tiselius moving boundary method. There is a strong correlation (r = 0.99) between the electrophoretic mobilities determined by the two techniques. The electrophoretic behavior of charged particles smaller than very low density lipoproteins (VLDL) is not markedly perturbed by a 0.5% agarose matrix, and variations in mobility primarily reflect differences in particle valence and density of surface charge. Application of electrokinetic theory to derive protein and lipoprotein net charges from the electrophoretic mobilities in agarose yields a quantitative delineation of lipoprotein electrophoretic migration patterns wherein the beta mobility region comprises a surface potential range of -4.5 to -7.0 mV; the pre-beta region a range of -7.0 to -10.5 mV; the alpha mobility region a range of -10.5 to -12.5 mV and the serum albumin region a range of -12.5 to -14.0 mV. Because protein conformation and charge are critical in metabolic regulation, the agarose gel electrophoresis technique provides a valuable analytical tool that should help to elucidate further details of the structure-function relationships of serum lipoprotein particles.

Electrochemistry↗
PubMed2005

Spatio-temporal distribution of Plasmodium falciparum and p. Vivax malaria in Thailand.

Malaria incidence data at the district level from 1997 to 2002 and total malaria case data from 1965 to 2002 in Thailand were analyzed to determine the spatial and temporal dynamics of Plasmodium falciparum and P. vivax malaria incidence. Over the 37-year period, there was a 35-fold reduction in the incidence rates of P. falciparum malaria (11.86% in 1965 versus 0.34% in 2002) and a 7-fold reduction in P. vivax malaria (2.89% in 1965 versus 0.40% in 2002). The incidence ratio of P. falciparum to P. vivax malaria was reduced from 4.1 to 0.8 during this period. Malaria incidence rate exhibited the most rapid reduction between 1975 and 1985, coinciding with the introduction of a combination of antifolate drugs (sulfadoxine-pyrimethamine). The distribution maps of P. falciparum and P. vivax malaria incidence rates indicated a high spatial heterogeneity. The Thailand-Myanmar and Thailand-Cambodia border areas, where migration of foreign workers was pronounced, had the highest incidence rates for P. falciparum, P. vivax, and mixed-species infections. Transition probability analysis based on the malaria incidence rate among Thai residents indicated that there was an overall trend of decrease in the number of malaria cases and the number of high incidence districts between 1997 and 2002. High spatial variation in malaria incidence and local human migration patterns suggest that malaria control measures need to be adjusted according to local environmental and demographic settings.

Animals↗
PubMed2005

Genotyping of Uruguayan Human adenovirus isolates collected between 1994 and 1998.

Adenoviruses are one of the most frequent causative agents of acute lower respiratory infections in infants and young children. Twenty-three adenovirus isolates from nasopharyngeal aspirates of children hospitalized for acute lower respiratory infections in Uruguay between 1994 and 1998 were studied by restriction enzyme analysis. The genomic analysis showed that 60.9% (n = 14) of isolates belonged to the species Human adenovirus C (HAdV-C) and 31.9% (n = 9) to the species Human adenovirus B (HAdV-B). Whereas some isolates could be classified according to the published profiles into genotype or genomic variant, others displayed migration patterns not allowing classification. Eight isolates (89%) of HAdV-B corresponded to the Ad7h genotype that has been associated with severe and fatal pneumonia and necrotizing bronchiolitis in children in South America. The isolates of HAdV-C showed a great variability in accordance with the data published earlier.

Adenovirus Infections, Human↗
PubMed2005

[Characteristics of melting and solidification process of fly ash from refuse incinerator].

This study was conducted to investigate the migration patterns of main compositions of the fly ash from refuse incinerator during melting and solidification process. The experiment was performed in a high temperature melting furnace with temperature controlled. X-ray fluorescence spectroscopy (XRF) and X-ray diffractometer (XRD) were used to analyzed the fly ash treated. The parameters investigated included main compositional contents, phase constituents, alkalinity, vaporation rate, volume reduction rate. The results show: (1) During the melting and solidification process, the contents of CaO, Al2O3, and SiO2 in fly ash increased as the temperature went up, but element Cl and S decreased from initial 20.59%, 10.74% to final 0.15%, 0.22%, respectively. This suggests that higher amount of Cl and S in original fly ash could lead to more vaporation in the form of chloride and calcium salfate in the process, which was further verified by XRD analyzing result. (2) The alkalinity decreased as melting temperature increased, but tended to be stable and maintained around 0.95 after temperature reached flowing temperature. (3) The decomposition and vaporation of the salts in the fly ash mainly occurred in the temperatures between 1150 degrees C and 1260 degrees C, which was approximately 100 degrees C lower than melting temperature.

Air Pollutants↗
PubMed2005

[Sociocultural diversity and medical education].

Global migration patterns have led to increasingly diverse populations, and physicians must learn to work effectively with patients from diverse backgrounds. However, some aspects of medical education may actually reinforce the idea that physicians do not need to take social and cultural differences into consideration in their work. In order to train physicians who are capable of providing quality care to patients from diverse backgrounds, it will be important to integrate the concept of cultural competence into all aspects of medical training, such that it will cease to be perceived as an "optional" aspect of medicine.

Cultural Diversity↗
PubMed1996

Is MS an auto-immune disease or a chronic gammaherpesvirus infection?

The geographical-epidemiological findings of MS over the past 75 years are reviewed. Evidence concerning PR latitude-gradients, clusters, migration patterns, and enhancement-protective factors are critically reviewed and analyzed. The evidence in genetics, twin-studies and auto-immune theories are also thoroughly scrutinized as to their possible involvement as causative factors in MS- and found to be somewhat lacking. Environmental discoveries in the Faroes and Key West clusters are reviewed for possible similar environmental causes by a deadly agent. Exogenous-environmental candidate agents over the past 35 years from measles to Marek's are reviewed and analyzed. The undisputed positive laboratory findings of MDV are discussed in relation to Bray's unusually high positive findings with EBV antigen and MS serums. The important discovery of HHV-6 in oligodendrocytes of MS brains but not controls is considered and how this might relate to MDV. The conclusion is that genetics are indeed important in the natural resistance of individual immune systems to invading infectious agents (especially herpesviruses) but genetics in general have little to do with the pathogenesis of multiple sclerosis (but HHV-6, EBV, and MDV do).

Autoimmunity↗
PubMed1991

Importance of migrants infected with Onchocerca volvulus in west African river valleys protected by 14 to 15 years of Simulium control.

A study was done to determine the importance of human migration from non-controlled endemic onchocerciasis foci to the river valleys that have been protected for the past 14 to 15 years by the vector control operations of the Onchocerciasis Control Programme in West Africa. The aim of the study was to assess the contribution of migrants to the prevalence and intensity of infection in villages from 5 major river valleys and their potential role in causing relapse of transmission once the vector is allowed to return. In Burkina Faso the migrant population varied from 0.0% to 18.1% of the village population, and averaged 4.9%. Migrants accounted only for 0.6% of the population in Ghanaian and Ivorian villages along the Black Volta river. The prevalence of infection was significantly higher in migrants (8.2%) than in non migrants (1.1%) in the surveyed villages in Burkina Faso, and 1.5% of migrants had infections with more than 16 microfilariae per snip as against 0.2% of non migrants. Nearly all infected migrants came from the south of the Côte d'Ivoire. The study shows that human migration has caused the importation of Onchocerca volvulus from non-controlled areas. However, the epidemiological importance of this phenomenon is limited because of the very small number of infected migrants per village while two-third of the infected migrants are believed to be infected with the less pathogenic forest strain of the parasite. Because migration patterns changes geographically and over time similar studies will be continued on a regular basis.

Animals↗
PubMed2006

Ashkenazi founder BRCA1/BRCA2 mutations in Slovak hereditary breast and/or ovarian cancer families.

Germline mutations in BRCA1 and BRCA2 have been predominantly associated with the breast and ovarian cancers. Two mutations in BRCA1 (185delAG and 5382insC) and one mutation in BRCA2 (6174delT) are common in Ashkenazi Jewish population. To determine the proportion of these founder mutations, we analyzed DNA samples of 120 Slovak hereditary breast and/or ovarian cancer (HBOC) suspected families. Two particular exons of BRCA1 (2, 20) and 11N segment of BRCA2 were screened by single strand conformation polymorphism (SSCP) followed by DNA sequencing of fragments showing abnormal migration pattern. Mutational analysis revealed that 7 out of 20 (35%) families with detected BRCA1/BRCA2 pathogenic alteration harbored one of three Jewish mutations: five families with 5382insC, one family with 185delAG and one family with 6174delT. Interestingly, we have noted a very rare phenotype, when 5382insC in BRCA1 co-segregated also with endometrial carcinoma. Similarly to the studies from other countries of Central and Eastern Europe, the most frequent pathogenic alteration found was 5382insC that accounted for 1/4 of all gene defects detected. Following the high proportion of Ashkenazi Jewish founder mutations in Slovak HBOC families, a pre-screening for at least 5382insC mutation in individuals at even moderate risk would be appropriate.

Adult↗