A micro-sample critical point drying device for small SEM and TEM specimens.
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Female↗
Biomedical subjects
S D Russell
Publications and source records attributed to S D Russell.
A method for improved resolution for fluorescence microscopy using plastic-embedded material subjected to resin extraction.
A protocol is given that uses NaOH, benzene, acetone and methanol to extract epoxy resins from semithin sections. Such sections appear superior to paraffin or unsectioned materials for fluorescence microscopic observations. Use of ultrarapid films (e.g., Kodak T-Max P3200) at ISO 3200 minimizes fading without use of antifading agents and without introducing unacceptable photographic grain size.
Epoxy Resins↗
Isolation of Fixed and Viable Eggs, Central Cells, and Embryo Sacs from Ovules of Plumbago zeylanica.
Three alternative protocols for light microscopy, electron microscopy, and biochemical characterization of isolated megagametophytic tissues are described employing enzymic maceration and microdissection of living and fixed ovular tissue of Plumbago zeylanica. Morphologically well preserved megagametophytes are obtained using fixed ovules in two different regimes (nearly 40 and 60% yield, respectively). Fluorescein diacetate-positive megagametophytic cells are recovered in nearly 20% of unfixed ovules using the third regime.
Journal Article↗
Thyroid hormone induces a nerve-independent precocious expression of fast myosin heavy chain mRNA in rat hindlimb skeletal muscle.
The appearance of the mRNA for the adult fast IIB myosin heavy chain (MHC) was examined during postnatal development of rats using an S1 nuclease assay. In normal rats, a large increase in the adult MHC mRNA began at 6-7 days after birth, whereas daily injections of newborn rats with 3 micrograms of triiodothyronine (T3) resulted in a precocious increase of the mRNA as early as 3 days after birth. Injection of a range of doses of T3 demonstrated that a large effect was obtained between 30 and 300 ng of T3/day/rat. Fast myosin protein was also precociously induced over the same range of T3 doses. This effect was also seen in denervated muscles, and muscles responded similarly to the different doses of T3 whether they were denervated or not. These results suggest that either thyroid hormone or some circulating factors induced by thyroid hormone are limiting factors in controlling the neonatal-to-adult fast MHC transition and that these factors may act directly on muscle tissue.
Animals↗
Two-Dimensional Electrophoretic Studies of the Proteins and Polypeptides in Mature Pollen Grains and the Male Germ Unit of Plumbago zeylanica.
Three fractions (male germ unit [MGU]-rich, cytoplasmic-particulate and water-soluble proteins) were isolated from pollen of Plumbago zeylanica L. Proteins were extracted using a phenol procedure and polypeptide patterns were compared on one- and two-dimensional polyacrylamide gels. The MGU-rich fraction contains the sperm and vegetative nucleus of the pollen grain and yielded 427 spots >33 kilodaltons. The cyto-plasmic-particulate fraction contained 515 spots >33 kilodaltons. The third fraction consisted of water-soluble proteins and polypeptides from the pollen cytoplasm, in which 285 spots (>33 kilodaltons) were identified. Of 133 polypeptide spots suitable for comparison, 18 were unique to the MGU-rich fraction, 3 to the cytoplasmic-particulate fraction, 14 to the water-soluble fraction, 65 were common to two different fractions (and absent in one), and 33 were common to all three of the fractions examined.
Journal Article↗
Isolation of Sperm Cells from the Pollen of Plumbago zeylanica.
Intact sperm cells of Plumbago zeylanica were released from mature pollen grains near anthesis using osmotic shock with 20% sucrose. Sperm cell yields of up to 75% can be attained by differential centrifugation using a clinical centrifuge with concentrations of up to 8.8 x 10(6) cells/milliliter. Such ;gametoplasts' remain intact for up to 24 hours according to Evan's blue exclusion and can be used for characterization or physiological manipulation.
Journal Article↗
Preferential fertilization in Plumbago: Ultrastructural evidence for gamete-level recognition in an angiosperm.
Gametic fusion patterns in the angiosperm Plumbago zeylanica were determined by using cytoplasmically dimorphic sperm cells differing in mitochondrion and plastid content and then identifying paternal organelles through their ultrastructural characteristics within the maternal cytoplasm at the time of fertilization. The virtual absence of plastids within the sperm cell that is physically associated with the vegetative nucleus allows paternal plastids to be used to trace the fate of the two male gametes after fusion. Such paternal plastids were present in the egg in >94% of the observed cases, indicating the preferential fusion of the plastid-rich, mitochondrion-poor sperm cell with the egg. In only one instance did the opposite pattern occur. Since the possibility of this result occurring as the consequence of chance in random fusions is <1 in 7000, this represents strong evidence for the presence of a final putative recognition event occurring at the gametic level.
Journal Article↗
Curing and commerce: changes in an indigenous medical practice in a highland Philippine town.
The intrusion of the capitalist mode of production in Third World countries is usually accompanied by the expansion of cosmopolitan medicine. In most multi-ethnic societies, indigenous medical practices continue to persist, if not thrive, under these conditions for a variety of reasons. Urbanizing areas in particular may become focal points for the emergence of innovative role adaptations among indigenous curers. This paper describes the career development of an indigenous medical specialist in a highland Philippine town. The purpose is to suggest the importance of examining the lifestyle and socio-economic strategies pursued by curers in similar contexts. Such analysis can aid in the process of understanding the way in which particular individuals can perform significant buffer roles that promote the continued viability of medically plural practices and beliefs.
Commerce↗
Denervation supersensitivity in skeletal muscle: analysis with a cloned cDNA probe.
Motor neurons regulate the acetylcholine sensitivity of the muscles they innervate: denervated muscle fiber become "supersensitive" to acetylcholine, due to insertion of newly synthesized acetylcholine receptors (AChRs) in the plasma membrane. We used hybridization analysis with a cloned cDNA specific for AChR alpha-subunit to compare the abundance of AChR mRNA in innervated and denervated adult mouse muscles. Within 3 d of denervation, levels of AChR mRNA increased 100-fold; levels of actin mRNA changed little. The increase in AChR mRNA level was sufficiently large and rapid to account for denervation supersensitivity.
Actins↗
Relative usefulness of measuring polyamines in serum, plasma, and urine as biochemical markers of cancer.
Serial samples of plasma and serum were collected in the morning and afternoon from cancer patients, along with 24-h urine specimens. Values for serum and plasma samples taken at the same time from the same patient differed little, suggesting that either procedure is acceptable for polyamine analysis. Increases in concentrations of putrescine and spermidine in serum and plasma correlate well with such increases in 24-h urine samples. Spermidine concentrations in sera were consistently about 10-fold lower than corresponding urine values. Putrescine concentrations were 10- to 100-fold different. The variation in putrescine values may be due to its more active metabolism by diamine oxidase, an enzyme known to be present in serum. Concentrations of polyamines in serum and urine increased in response to effective chemotherapy.
Bleomycin↗
Bridging patients to cardiac transplantation.
Potential recipients of heart transplants have the most advanced form of congestive heart failure, in which standard therapy fails to maintain clinical stability. In the absence of guidelines derived from evidence obtained in clinical trials, caring for these patients becomes a challenge. A successful approach requires the proper coordination of surgical and nonsurgical strategies, including revascularization and valvular surgery as well as mechanical ventricular support and medical strategies. Intensive medical therapy is the most commonly used approach for prolonged bridging to transplantation. Although carefully individualized regimens are necessary to achieve desired goals, most centers adopt a fairly standardized approach involving vasodilators, diuretics, and inotropic support. Bridging patients with cardiac decompensation to transplantation presents a major therapeutic challenge. Appropriate strategies will maximize patients' chances that the bridge from decompensation to transplantation remains intact. (c)2000 by CHF, Inc.
Journal Article↗
Child abuse and neglect in North Carolina day care programs.
A study of child abuse and neglect complaints in child day care programs revealed factors affecting the filing of complaints, as well as problems with the investigation of complaints filed with the North Carolina Office of Child Day Care Licensing. The authors specify the cause of the problems and offer recommendations for improvement.
Child Abuse↗