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Biomedical subjects

I D Godwin

Publications and source records attributed to I D Godwin.

13 recordsLinked to original sources

Application of inter simple sequence repeat (ISSR) markers to plant genetics.

Microsatellites or simple sequence repeats (SSRs) are ubiquitous in eukaryotic genomes. Single-locus SSR markers have been developed for a number of species, although there is a major bottleneck in developing SSR markers whereby flanking sequences must be known to design 5'-anchors for polymerase chain reaction (PCR) primers. Inter SSR (ISSR) fingerprinting was developed such that no sequence knowledge was required. Primers based on a repeat sequence, such as (CA)n, can be made with a degenerate 3'-anchor, such as (CA)8RG or (AGC)6TY. The resultant PCR reaction amplifies the sequence between two SSRs, yielding a multilocus marker system useful for fingerprinting, diversity analysis and genome mapping. PCR products are radiolabelled with 32P or 33P via end-labelling or PCR incorporation, and separated on a polyacrylamide sequencing gel prior to autoradiographic visualisation. A typical reaction yields 20-100 bands per lane depending on the species and primer. We have used ISSR fingerprinting in a number of plant species, and report here some results on two important tropical species, sorghum and banana. Previous investigators have demonstrated that ISSR analysis usually detects a higher level of polymorphism than that detected with restriction fragment length polymorphism (RFLP) or random amplified polymorphic DNA (RAPD) analyses. Our data indicate that this is not a result of greater polymorphism genetically, but rather technical reasons related to the detection methodology used for ISSR analysis.

Autoradiography↗

Assessment of genome origins and genetic diversity in the genus Eleusine with DNA markers.

Finger millet (Eleusine coracana), an allotetraploid cereal, is widely cultivated in the arid and semiarid regions of the world. Three DNA marker techniques, restriction fragment length polymorphism (RFLP), randomly amplified polymorphic DNA (RAPD), and inter simple sequence repeat amplification (ISSR), were employed to analyze 22 accessions belonging to 5 species of Eleusine. An 8 probe--3 enzyme RFLP combination, 18 RAPD primers, and 6 ISSR primers, respectively, revealed 14, 10, and 26% polymorphism in 17 accessions of E. coracana from Africa and Asia. These results indicated a very low level of DNA sequence variability in the finger millets but did allow each line to be distinguished. The different Eleusine species could be easily identified by DNA marker technology and the 16% intraspecific polymorphism exhibited by the two analyzed accessions of E. floccifolia suggested a much higher level of diversity in this species than in E. coracana. Between species, E. coracana and E. indica shared the most markers, while E. indica and E. tristachya shared a considerable number of markers, indicating that these three species form a close genetic assemblage within the Eleusine. Eleusine floccifolia and E. compressa were found to be the most divergent among the species examined. Comparison of RFLP, RAPD, and ISSR technologies, in terms of the quantity and quality of data output, indicated that ISSRs are particularly promising for the analysis of plant genome diversity.

Base Sequence↗

Vitamin B12 and folate. Pediatric reference ranges.

Pediatric reference ranges were obtained for vitamin B12 and folate (Quantaphase radioimmunoassay, BioRad, Hercules, Calif) using a large hospital population. Data were analyzed employing the Hoffman approach, which was computer adapted. For folic acid, the range for subjects aged 1 to 12 years averaged 5.7 to 31.3 nmol/L for female subjects and 4.5 to 27.0 nmol/L for male subjects. There was a significant decrease in folic acid concentrations after 13 years, the upper limit being 16.5 nmol/L in female subjects and 19.9 nmol/L in male subjects. For vitamin B12, the values in the 0- to 1-year age group were nearly double those in the 13- to 18-year age group. For female subjects, the values in the 0- to 1-year age group were 168 to 1116 pmol/L and in male subjects were 216 to 891 pmol/L. At 13 to 18 years, for female subjects the values were 158 to 637 pmol/L and for male subjects, 134 to 605 pmol/L.

Adolescent↗

Demographics map route to MSV membership growth.

The Medical Society of Virginia's new database revealed 1) an aging membership with a high percentage of dues exemptions; 2) an apparent reluctance on the part of many young physicians to consider MSV dues a worthwhile investment; and 3) a marked underrepresentation in the MSV membership of women, who now comprise nearly half of most medical school classes. In order to maintain a viable organization, the Medical Society of Virginia must do more to attract those who are underrepresented in the membership. This is not a choice. It is an imperative.

Databases, Bibliographic↗

Within-person fluctuations of serum cholesterol and lipoproteins.

The National Cholesterol Education Program has begun a National Campaign to screen millions of adult Americans for serum cholesterol. To determine whether such random samples represent an individual's true lipoprotein status, we measured fasting total serum cholesterol and lipoproteins, on a weekly basis for 4 weeks, in 20 subjects ages 22 to 63 years. Duplicate samples were tested by two standardized laboratories, each on five consecutive days. Variations of more than +/- 20% in the serum levels of total cholesterol, low-density lipoprotein cholesterol, and high-density lipoprotein cholesterol were seen in 75%, 95%, and 65% of the subjects, respectively. On retesting, 40% of the subjects moved in or out of one "risk category"; and in 10% two categories, from "desirable" to "high risk," or vice versa. These data demonstrate that random testing may fall to detect wide fluctuations in the levels of serum lipoproteins, and therefore result in erroneous risk assignment or therapeutic intervention.

Adult↗

Normal hematologic values obtained with a Coulter counter, model S.

A survey was made of hematologic values obtained with the Coulter Counter, Model S, at American Medical Laboratories, Inc. Blood specimens from 6,887 outpatient men, women, and children were analyzed according to age and sex. Patients being seen by nephrologists, hematologists, and oncologists were excluded from the study. The mean values for white blood cell counts, mean corpuscular volume, mean corpuscular hemoglobin, and mean corpuscular hemoglobin concentration correlated well with values frequently quoted as normal. However, the mean values for hemoglobin, hematocrit, and red blood cell counts were slightly lower than the commonly accepted normal mean values. This may be a result of newer and more accurate methods of hematologic analysis.

Adolescent↗

Single image pericardial effusion evaluation with technetium compounds.

Three cases of suspected pericardial effusion were evaluated with rapid, noninvasive procedure, combined use of macroaggregated albumin technetium 99m and human serum albumin technetium 99m to produce a single radiography showing the heart, liver, and lung perfusion simultaneously. This technic confirmed the diagnosis of pericardial effusion in two cases and ruled out this possibility in the third case.

Adult↗