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Biomedical subjects

M C Williams

Publications and source records attributed to M C Williams.

227 records · Page 13Linked to original sources
PubMedDate not supplied

Hormonal modulation of Ishikawa cells during three-dimensional growth in vitro.

OBJECTIVES: The Ishikawa endometrial cancer cell line is hormonally responsive, expressing estrogen and progesterone receptors (ER, PR) when grown in traditional monolayer culture. The purpose of this paper is to demonstrate a three-dimensional spheroid culture system for cancer cells. We used this system to determine the response of the Ishikawa cell line to estradiol-17 beta (E), tamoxifen (T), megestrol acetate (MA), and progesterone (P). METHODS: Ishikawa cells were incubated in polyurethane culture bags using phenol red-free media containing ethanol (0.1%, controls), E (1 mumol, or 1 nmol), T (1 mumol, or 10 nmol), MA (1 mumol, or 10 nmol), or P (1 mumol). Cellular morphology was assessed by hematoxylin and eosin staining, and expression of estrogen and progesterone receptors was determined immunohistochemically using an immunoperoxidase technique. RESULTS: Cells in control cultures demonstrated minimal organization and lacked hormone receptors. In contrast, cells exposed to either E or T displayed significant glandular formation, with multicellular, microvilli-rich, columnar epithelia exhibiting polarized nuclear arrangements. Within 4 weeks, E- and T-treated cultures showed upregulated nuclear staining for PR, with little ER present. Cells treated with MA or P showed less glandular organization but expressed ER with PR downregulation. CONCLUSIONS: These data support the use of this novel three-dimensional culture system to study the modulation of tumor cell biologic activity in response to hormonal agents. Future applications of this model include examining in vitro responsiveness of cancer cell lines to additional biologic agents and chemotherapeutic regimens.

Cell Culture Techniques↗
PubMedDate not supplied

Modulators of prostaglandin E2 synthesis in human amnion.

OBJECTIVE: The purpose of these studies was to determine the effects of the essential fatty acid, linoleic acid, and the commonly used non-steroidal anti-inflammatory agents, aspirin and acetaminophen, on the rate of prostaglandin (PG) biosynthesis by human amnion cells. METHODS: Amnion cells were isolated from term, normal pregnancies and grown to confluence. Cells were incubated with control or medium containing 100 mumol/L linoleic acid. Cells were also incubated with control medium or medium containing 10 or 100 micrograms/mL aspirin or acetaminophen. RESULTS: Following an initial delay, amnion cells exposed to linoleic acid exhibited a significant increase in PGE synthesis. Both aspirin and acetaminophen in clinically relevant concentrations had a significant inhibitory effect on amnion cell PGE synthesis. CONCLUSIONS: Linoleic acid has a stimulatory effect and aspirin and acetaminophen have an inhibitory effect on PGE synthesis in human amnion cells in culture. We speculate that dietary habits, supplement ingestion, and over-the-counter drug use may affect amnion cell PG production. In view of the potential importance of intrauterine PG production in normal and abnormal labor, further study in this area is indicated.

Acetaminophen↗
PubMedDate not supplied

Photosensitizing effects of Cymopterus watsonii and Cymopterus longipes in chickens and turkey poults.

Two-week-old straight-run white broiler chicks and 2-week-old straight-run white turkey poults were fed seed or whole plants Cymopterus watsonii or seed of Cymopterus longipes at 0.4, 0.8, and 1.6% of body weight, and then placed in sunlight for 5 hours each day for 7 days. All plant material produced moderate to severe photosensitivity in chicks. Toxic signs included photophobia; red discoloration of beak, comb, and feet; loss of feathers in the periorbital area; dried serous fluid on comb and edge of beak; keratoconjunctivitis; and multiple lesions on feet and legs. Turkey poults showed a syndrome similar to that of chicks. Mortality was particularly high in turkeys fed C. longipes seed. Toxic signs in turkeys 6 weeks after treatment included tremors in the legs; upturning and shortening of the upper beak; and shortening disfigurement, and gangrene of the toes. Two phototoxic furocoumarins, oxypeucedanin and isoimperitorin, were isolated from C. longipes seed. Either compound, administered orally, produced photosensitivity in 2-week-old chicks.

Animals↗
PubMedDate not supplied

A comparison of birth weight and weight/length ratio for gestation as correlates of perinatal morbidity.

OBJECTIVE: The purpose was to evaluate a low weight to length ratio as a correlate of perinatal morbidity and mortality. STUDY DESIGN: Data from the Collaborative Perinatal Project for infants of 34 weeks' gestation or more were evaluated. Associations between the weight to length ratio of < 10% (low weight to length) and birth weight of < 10% (small for gestational age) by gestational age and gender, perinatal depression, dysmaturity, cerebral palsy, and neonatal mortality were evaluated. RESULTS: A low weight to length ratio and small for gestational age status were associated with most markers of perinatal morbidity and mortality in term and preterm infants. In infants not small for gestational age, a low weight to length ratio was associated with increased morbidity and mortality (relative risk of 1.9 to 4.2) in term infants, and with perinatal depression (relative risk of 2.9) in preterm infants. Logistic regression found low weight to length ratio was a better independent correlate than small for gestational age status for all markers assessed and found low weight to length ratio was significantly associated with all morbidity and mortality markers in infants not small for gestational age. CONCLUSION: Low weight to length ratio, a marker for asymmetric growth restriction, is correlated with perinatal morbidity, even in infants not small for gestational age.

Birth Weight↗
PubMedDate not supplied

Twins, asymmetric growth restriction, and perinatal morbidity.

OBJECTIVE: Our objective in this study was to evaluate decreased weight/length ratio as a correlate of perinatal morbidity in twins. STUDY DESIGN: Rates of weight/length ratio less than 10% (low WL) were compared in 986 neonates from twin gestations and 4929 matched singletons. Low WL was compared with birth weight less than 10% (SGA) and 25% birth weight discordance as a marker for perinatal depression and neonatal mortality. RESULTS: Both SGA (42% vs 8%) and low WL (38% vs 8%) occurred more commonly in twins. Low WL was a better correlate of depression and mortality than SGA or 25% birth weight discordance. After adjustment for major anomalies, prematurity, and low WL, perinatal morbidity in twins and singletons did not differ. CONCLUSIONS: Low WL, a marker of asymmetric growth restriction, is a better marker for perinatal morbidity in twins than SGA or 25% discordance. Twins and singletons have similar rates of perinatal morbidity and mortality after adjustment for anomalies, prematurity, and growth restriction.

Body Height↗