Search PubMed⌕ Search

Biomedical subjects

S Curtis

Publications and source records attributed to S Curtis.

86 records · Page 5Linked to original sources
PubMed1983

Natural history of cerebral complications of coronary artery bypass graft surgery.

We reviewed 1,669 patients who survived coronary artery bypass graft surgery between 1969 and 1981. A total of 75 cerebral complications were identified, including (1) altered mental state, (2) stroke, and (3) seizure in 64 patients (3.8%). Altered mental state (delirium, hypoxic-metabolic encephalopathy) occurred in 57 (3.4%). Postoperative arrhythmias were associated with an increased risk of altered mental state. Cerebral infarction occurred in 13 (0.8%). Patients who suffered stroke had a higher occurrence of carotid bruits and history of peripheral vascular disease. Seizures occurred in five patients (0.3%). Mortality in patients with a neurologic complication was 29%.

Brain Diseases↗
PubMed1983

Effect of estradiol on human breast cancer cells in culture.

Conditions are described for growing and maintaining the estradiol sensitivity of the human breast cancer cell line ZR-75-1 both in monolayer and suspension cultures. Either newborn calf or fetal calf serum can be used in the culture medium, but an effect of estradiol on growth of the cells was only observed reproducibly if the serum was first treated with dextran-charcoal. Sulfatase treatment of the sera prior to dextran-charcoal treatment did not decrease cell growth in the absence of added estradiol, indicating that estrogen sulfates are unlikely to contribute to cell growth in dextran-charcoal-treated sera. In monolayer cultures, estradiol increased both the growth rate and final saturation density of the cells for each individual plating density tested in a dose-dependent manner with maximal stimulation occurring between 10(-10) and 10(-8) M estradiol. Estradiol also markedly increased the ability of the cells to grow both in suspension and semisolid Methocel cultures. In suspension, the cells grew as tight balls which clustered together to give small organoid-like structures reaching diameters of 4 mm and composed of an outer shell of living cells containing a central cavity of necrotic cells. In the absence of estradiol in both monolayer and suspension, the cells went through a limited and constant number of divisions and then stopped, such that the final cell number was determined by the initial plating density. In the presence of estradiol, this block was removed such that in monolayer cultures the final cell number was independent of plating density. A major loss of estradiol response was found if the cells were grown for 7 to 14 days in the absence of estradiol. This loss of response appeared to be due to a loss of ability to grow rather than to selective cell death within the population.

Breast Neoplasms↗
PubMed1982

Treatment of cancer with heavy charged particles.

A clinical radiotherapeutic trial using heavy charged particles in the treatment of human cancers has accrued over 400 patients since 1975, 378 of whom were treated with particles and 28 with low LET photons as control patients. Heavy charged particle radiotherapy offers the potential advantages of improved dose localization and/or enhanced biologic effect, depending on particle selected for treatment. Target sites have included selected head and neck tumors, ocular melanomata, malignant gliomata of the brain, carcinoma of the esophagus, carcinoma of the stomach, carcinoma of the pancreas, selected juxtaspinal tumors and other locally advanced, unresectable tumors. A Phase III prospective clinical trial has been started in carcinoma of the pancreas using helium ions. Phase I-II studies are underway with heavier particles such as carbon, neon and argon ions in order to prepare for prospective Phase III trials. Silicon ions are also under consideration for clinical trial. These studies are supported by the United States Department of Energy and National Institutes of Health.

Adult↗
PubMed1982

Effect of combined misonidazole and accelerated neon ions on a human melanoma transplanted into nude mice.

The response to accelerated neon ions of human Nall melanomas growing in nude mice was measured by an in vitro colony-forming assay following in situ tumor irradiation in the midposition of a 10-cm extended-peak ionization region. Values of the relative biological effectiveness (RBE) for peak neon ions compared with 60Co gamma radiation were 3.2 and 3.4, respectively, at the 1% and 10% survival levels. Following irradiation with peak neon ions, the repair of potentially lethal damage (PLD) was comparable to that observed after gamma irradiation. When misonidazole (1 mg/g intraperitoneal dose) was administered in combination with extended-peak neon ions, the drug enhancement ratio (ER) at the 1% survival level was 1.5 if the tumors were removed and plated in vitro immediately following irradiation, and 1.9 if tumor excision and plating were delayed for greater than 6 hours. Administration of misonidazole completely inhibited PLD repair following either gamma irradiation or extended-peak neon-ion irradiation.

Animals↗
PubMed1981

Effects of prepartum protein restriction in the beef cow on immunoglobin content in blood and colostral whey and subsequent immunoglobin absorption by the neonatal calf.

Protein intake of first-calf beef heifers was restricted during the last 100 days of gestation, and the effects on passive transfer of colostral immunoglobins from the cow to the neonatal calf were examined. There were no significant correlations between concentration of immunoglobins (IgM, IgG1 and IgG2) in the sera or colostrum of the cow and prenatal crude protein consumption (.52 to .98 kg crude protein/day). Absorption of certain colostral immunoglobins (IgG1, and IgG2) by the calf were positively correlated (P less than .01) at 12, 18, 24 and 36 hr after birth to the maternal crude protein consumption. Colostrum was collected from the first milkings of pluriparous dairy cows, and then freeze-dried, mixed and reconstituted to be equivalent to 1 liter of colostrum. Mean IgG1 concentrations for the high and low protein groups were 6.02 +/- .90 and .78 +/- .15 mg . ml-1 (P less than .01), respectively. No relationship (P greater than .05) was found between the concentration of IgM in calf sera and daily crude protein intake of the dam. These data indicate that there was a selective decrease in absorption of IgG1 and IgG2 in calves from heifers fed low protein prenatal diets.

Animals↗
PubMed1979

DNA sequence organization in the alga Euglena gracilis.

The sequence organization of nuclear DNA in the single-celled alga Euglena gracilis has been studied by a combination of techniques: (1) the comparison of the reassociation kinetics of DNA fragments 300, 2000 and 8100 nucleotides long; (2) the reassociation of 32P-labeled DNA fragments of various lengths with driver fragments 300 nucleotides long; (3) the hyperchromicity of DNA structures formed by the reassociation of repetitive sequences; (4) and the direct measurement of the size of the duplex regions of reassociated repetitive DNA resistant to S1 nuclease. The single copy DNA sequences are approximately 1500 nucleotide pairs long and are interspersed with repetitive DNA sequences. The repetitive DNA, consisting of both highly repetitive and middle repetitive sequences, consists of one fraction of nucleotide sequences (0.67) with an average size of 4900 nucleotide pairs and a second fraction (0.33) with an average size of 1000 nucleotide pairs, 34% of the DNA consists of foldback sequences which are present on 45% of the DNA 4000 nucleotides long.

Base Sequence↗
PubMed1968

Frog germ cells.

Explore the source record for details and available documents.

Animals↗
PubMed1968

Germ cell chimerism: absence in parabiotic frogs.

Embryos of the leopard frog deprived of primordial germ cells by treatment with ultraviolet light were joined in parabiosis with normal, unirradiated embryos. The irradiated member of the pair was not colonized by germ cells from its normal partner. Unlike the primordial germ cells of birds and mammals, the germ cells of frog embryos are not carried by the circulating blood.

Animals↗
PubMedDate not supplied

Androgen regulation of cell proliferation and expression of viral sequences in mouse mammary tumour cells.

The role of steroids in promoting cell proliferation is well established but the molecular mechanisms are not clear. The S115 mouse mammary tumour cell line provides a model system for molecular studies in vitro in that it exhibits in tissue culture both a positive proliferative response to androgens and a change from a transformed phenotype in the presence of androgen to a normal phenotype when androgen is removed. We have considered here the possible involvement of mouse mammary tumour virus (MMTV) in these processes. We have demonstrated the presence in S115 cells of MMTV-related sequences which are transcribed into RNA only in the long-term presence of androgen. Prolonged culture in the absence of androgen, which results in loss of proliferative response to androgen, is accompanied by loss of MMTV-related RNA and increased methylation of MMTV-related sequences.

Animals↗
PubMedDate not supplied

Proactive nursing: the evolution of a task force to help women with postpartum depression.

In response to several women who presented with postpartum depression in 1 year, a group of nurses developed a task force made up of hospital nurses, obstetricians, psychiatrists, pediatricians, family practitioners, lactation specialists, home care nurses, and mental health counselors. The purposes of this task force were to educate health care professionals about postpartum depression, to help identify women who might be affected, and to develop interventions for adjusting to parenthood. This article details the evolution of that task force, and how it has assisted not only the women but also the health care providers involved.

Community Health Nursing↗
PubMedDate not supplied

[The use of geographic indicators of mortality for planning health services: the experience in Great Britain].

The computation of standardized mortality ratio (SMR) is carried out at various geographical levels: by regional health authorities, district health authorities, and wards. Mortality disparities are correlated to differential living conditions. Areas showing a higher SMR are likely to be those with an under-privileged population. The relationship may be expressed graphically. On the basis of these findings, the Health Education Authority decided to implement policies aimed at: (i) decreasing cardiovascular mortality by 15 percent; (ii) decreasing the gap between under-privileged and "rich" districts by 15 percent. These objectives are expressed graphically in Fig. 4: line A must be replaced by line B. The conclusion reached is that the decrease in the mortality rate cannot be achieved by a single action on the part of health authorities, as the task of improving living conditions or modifying individual behavior patterns is beyond their reach. Nevertheless, these challenges can and should be overcome.

Cause of Death↗