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Biomedical subjects

S M Martin

Publications and source records attributed to S M Martin.

At least 91 records · Page 5Linked to original sources
PubMed1971

Lignofibrils on the external cell wall surface of cultured plant cells.

Small strands and bundles of strands extend from the outside surface of suspension-cultured cells of Daucus, Ipomoea, and Phaseolus into the medium. This fibrous cell coat is present in all samples from various growth stages but appears to increase in quantity in the order Ipomoea < Phaseolus < Daucus. The bundles are often many microns in length and display great variation in frequency, size, and form. Identification of the composition of the strands and bundles as lignin is consistent with the following observations: alkaline nitrobenzene oxidation of the strands to compounds which resemble monomers of wood lignin; resistance of the strands to pronase, trypsin, pectinase, and lipase; strong irreversible adsorption of heavy metals; deposition of silver granules by treatment with silver nitrate-hexamine reagent; extraction of the bundles with aqueous dioxane (Björkman procedure); presence in quantity of a structured form of Klason lignin; and existence of material giving a positive test with the Wiesner reagent. Large individual strands (lignofibrils) from Phaseolus show the form of a flat ribbon with very thin branches at irregular intervals. This form does not vary with preparatory techniques, although its electron opacity does. Intercellular spaces display considerable structure and sometimes contain sheets of fibrillar material merging with both the middle lamella between the cells and the surface bundles facing the medium. These sheets are probably another form of association of the lignofibrils. It is suggested that natural fibrous lignin may be a much commoner component of plant tissue than suspected hitherto.

Cell Fractionation↗
PubMedDate not supplied

Using laboratory-based surveillance data for prevention: an algorithm for detecting Salmonella outbreaks.

By applying cumulative sums (CUSUM), a quality control method commonly used in manufacturing, we constructed a process for detecting unusual clusters among reported laboratory isolates of disease-causing organisms. We developed a computer algorithm based on minimal adjustments to the CUSUM method, which cumulates sums of the differences between frequencies of isolates and their expected means; we used the algorithm to identify outbreaks of Salmonella Enteritidis isolates reported in 1993. By comparing these detected outbreaks with known reported outbreaks, we estimated the sensitivity, specificity, and false-positive rate of the method. Sensitivity by state in which the outbreak was reported was 0%(0/1) to 100%. Specificity was 64% to 100%, and the false-positive rate was 0 to 1.

Algorithms↗
PubMedDate not supplied

Implementing a network for electronic surveillance reporting from public health reference laboratories: an international perspective.

Electronic data reporting from public health laboratories to a central site provides a mechanism for public health officials to rapidly identify problems and take action to prevent further spread of disease. However, implementation of reference laboratory systems is much more complex than simply adopting new technology, especially in international settings. We describe three major areas to be considered by international organizations for successful implementation of electronic reporting systems from public health reference laboratories: benefits of electronic reporting, planning for system implementation (e.g., support, resources, data analysis, country sovereignty), and components of system initiation (e.g., authority, disease definition, feedback, site selection, assessing readiness, problem resolution). Our experience with implementation of electronic public health laboratory data management and reporting systems in the United States and working with international organizations to initiate similar efforts demonstrates that successful reference laboratory reporting can be implemented if surveillance issues and components are planned.

Clinical Laboratory Information Systems↗
PubMedDate not supplied

Blood donor rejection rate: HemoCue hemoglobin analyzer vs. microhematocrit.

This study compared 2 different methodologies: hemoglobin by the HemoCue instrument and hematocrit by the microhematocrit method, to determine if there were any significant difference in the values that could affect donor rejection rates. Literature from the 1960s to 1990s reveals a variety of methods for hemoglobin and hematocrit determinations as well as discussions on fingerstick versus earlobe capillary samples. The HemoCue hemoglobin analyzer is a relatively new technology that tests capillary specimens. The copper sulfate method, although the method of choice for measuring prospective donor hemoglobin levels for many years, was not a part of the study. The microhematocrit method has historically been used as the method for measuring hematocrit alone or as a secondary procedure when donors failed the copper sulfate screening test.

Blood Donors↗