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Biomedical subjects

S Stinson

Publications and source records attributed to S Stinson.

18 recordsLinked to original sources

Feasibility of cellular microencapsulation technology for evaluation of anti-human immunodeficiency virus drugs in vivo.

We investigated the feasibility of micro-encapsulation technology for the evaluation of anti-human immunodeficiency virus (HIV) drugs in vivo. The ability to place human cells in microcapsules with semipermeable membranes for implantation into test animals led to the development of this assay. The anti-HIV activity assay involves microencapsulating human T-lymphoblastoid cells sensitive to the cytopathic effects of HIV; the encapsulated cells are then implanted into athymic nude mice and recovered after drug treatment in vivo. A positive antiviral effect of the test substance is indicated by growth or survival of the virus-infected cells in the microcapsules. Several HIV-sensitive cell lines of T-lymphocyte, monocyte, and nonlymphocyte origin were examined for growth in microcapsules in vitro and in vivo. Light and electron microscopic analysis of the capsules and the human cells contained therein revealed the invasion of mouse immune cells and other adverse effects that could not be overcome by any of numerous technical modifications attempted. We conclude that cellular microencapsulation technology is not feasible for in vivo drug-testing protocols because of immunogenic reactions.

Animals

Intraoperative topical etidocaine for reducing postoperative pain after laparoscopic tubal ligation.

Self-reported postoperative pain was reduced significantly (P less than .05) for up to six hours in a group of ambulatory surgical patients with the application of 5 mL of 1% etidocaine to the banded portion of each fallopian tube after laparoscopic tubal ligation with Falope Rings in comparison to a control group receiving normal saline. The etidocaine group had less nausea and vomiting and smaller antiemetic and analgesic requirements than did the control group, though those results were not statistically significant.

Acetanilides

Morphology of Leishmania braziliensis: changes during reversible heat-induced transformation from promastigote to an ellipsoidal form.

Leishmania braziliensis, growing axenically at 26 C and transferred to 34 C, changes within 3 hr from the long slender motile promastigote form to an ellipsoidal form with a nonmotile flagellum. This transformation is reversible for heat treatments of up to 12 hr. In this study we show by light microscopic measurements that the cells decrease in length and increase in diameter at constant volume. Quantitative morphometry of electron micrographs further demonstrates that: the distance between nucleus and kinetoplast decreases; the kinetoplast enlarges slightly; the distance between adjacent subpellicular microtubules decreases; and that after 3 hr of heat treatment there is no change in mitochondrial morphology, but after 6 hr of heat treatment the mitochondria lose their cristae and no longer possess a clearly defined double membrane. These observations are compared with the morphological changes that occur normally in the gut of a sandfly and in the in vivo transformation occurring during infection of the mammalian host and of macrophage cultures.

Animals

Significance of ultrasound measurements of the head of the breech fetus.

Ultrasound measurements of head shape and size in 451 fetuses presenting as a breech were compared to those obtained in 1,880 fetuses presenting as a cephalic between 15 and 40 weeks' gestation. No statistically significant differences were found for the biparietal diameter (BPD), head circumference (HC), or cephalic index (CI) measurements between the two groups in uncomplicated pregnancies. The mean values for the CI were found to be lower for breech presenting fetuses in complicated pregnancies, indicating a trend for these fetuses to have a more dolichocephalic head shape.

Breech Presentation

Early prenatal attainment of adult metacarpal-phalangeal rankings and proportions.

As shown in 56 human embryos and fetuses between 15 and 104 mm in crown-rump length, "adult" metacarpal-phalangeal length rankings are attained by the seventh intrauterine week and near-adult bone-to-bone ratios or proportions by the theirteenth week. Micrometric measurements of optically-projected histological hand sections show relative elongation of the distals between the 15-29 mm and 30-44 mm crown-rump range, and relative reduction to radiogrammetrically-determined adult proportions by the 90-104 mm CRL.

Anthropology, Physical

Chest dimensions of European and Aymara children at high altitude.

This study compares the chest dimensions of European children raised at high altitude with those of Andean natives. The samples consist of 216 children between 8 and 14 years who attend the private French School in La Paz, Bolivia and 253 Aymara children of the same age who reside in the rural country of Arncoraimes, Bolivia. Compared to the Aymara children, the European children have larger chest depths and chest widths, but have smaller chest dimensions relative to stature. There is no difference between the two groups in the ratio of chest width to chest depth. The small relative chest size of the European children further expands the range of variation in chest dimensions among high altitude populations.

Adolescent