The use of thioesterase II as a rat mammary epithelial cell-specific marker

The avidin-biotin-peroxidase complex immunoperoxidase technique was employed to determine the intercellular distribution of thioesterase II in rat mammary glands. This enzyme is responsible for shifting the product specificity of the fatty-acid synthetase enzyme complex from long to medium chain fatty acids. Thioesterase II was found exclusively in the cells lining the lumen of the ductal and alveolar structures in glands from mature virgin (150 days old) and pregnant rats. The ductal cell staining intensity was considerably less than that of the alveolar cells in the mature virgin rat glands. No immunoreactive thioesterase II was found in the stromal, adipose, vascular, or myoepithelial components of the gland in the developmental stages examined. In the glands from immature virgin rats (40-45 days old) thioesterase II was again found only in the epithelial cells lining the lumen of the ductal and end-bud structures although this layer was usually more than one cell thick. Quantitative determination of thioesterase II activity in cytosol preparations revealed similar levels in mammary fragments from enzymatically-dissociated glands obtained from mature virgins and in end buds derived from immature virgins, but somewhat higher levels in mammary structures derived from late-pregnant animals. These immunohistological and biochemical results demonstrate thioesterase II's usefulness as a mammary epithelial cell-specific marker.

Response of end bud cells from immature rat mammary gland to hormones when cultured in collagen gel

End buds from 4- to 5-week-old rat mammary glands were isolated and cultured within a rat tail tendon collagen gel matrix. Media containing equine serum or porcine serum and cholera toxin promoted growth, but not the production of casein or thioesterase II, nor did they induce a state of differentiation as assessed by cell ultrastructure. Medium supplemented with only 5% porcine serum, insulin and cholera toxin did not support growth or differentiation. However, when prolactin, estradiol, progesterone and hydrocortisone were added to this medium, growth was stimulated greatly and a differentiated state was induced as assessed by the production of casein and thioesterase and by the appearance of a highly secretory ultrastructure.

Comparison of the growth of normal and neoplastic mouse mammary cells on plastic, on collagen gels and in collagen gels

The growth of normal and neoplastic mouse mammary cells was compared in primary cultures on plastic, on rat tail collagen gels and in rat tail collagen gels. Cells on plastic grew for the first few days, then stopped with only a 1- to 3-fold increase in cell number after 2 weeks in culture. Cells grown on or in collagen gels grew continuously over the 2-week culture period with up to 10-fold increase in cell number for cultures on collagen gels and a 20-fold increase for cells embedded in collagen gels. The difference in growth rates between cells grown in collagen gel and those grown on collagen gels was due, in part, to the three-dimensional growth of the colonies in collagen gel their two-dimensional growth on collagen gel. Cells grown on and in collagen gel can produce an electron-dense basal lamina-like structure which is associated with collagen IV and laminin as judged by immunofluorescence. Cells grown on plastic do not form this structure. Cis-OH-proline blocks the production of collagen and inhibits the growth of the cultured cells indicating collagen production to be involved in growth. Rat tail collagen gels are a superior substratum for the growth of mouse mammary cells and this may be related to the cells' ability to form a collagen IV-containing basal lamina-like structure.

Measurement of the response of HELA cells towards the radiomimetic activity of 12-O-tetradecanoylphorbol-13-acetate

The sensitivity of HeLa cells in the G2 phase of the cell cycle towards the radiomimetic activity of the tumor promoter 12-O-tetradecanoylphorbol-13-acetate (TPA) (Kinzel et al. (1980) Science, 210, 429-431) has been utilized to establish dose response relationships. This was accomplished by analysis of mitotic curves and determination of cells not affected, a measurement known to be dose dependent in the case of very low X-ray doses. Half maximal activity was exerted by TPA at approximately 5 X 10(-9) M concentration. Mechanistically, however, TPA seems to exert its activity through a route different from that of X-rays or other radiomimetic drugs for 2 reasons: (1) the cellular response does not increase proportionally with dose; (2) cells recover from G2 blockage even in the presence of TPA. Therefore it appears as if the tumor promoter acts indirectly by triggering an exhaustable cellular activity which leads to the radiomimetic response.

Effects of retinoic acid and tumor promoter 12-o-tetradecanoylphorbol-13-acetate (TPA) on the cell cycle of HeLa cells

The influence of retinoic acid (RA) - a modifier of tumor promotion - on the cell cycle of HeLa cells, and its ability to interfere with the early irradiation-like effects induced by the tumor promoter 12-O-tetradecanoylphorbol-13-acetate (TPA) has been investigated by a variety of different techniques. These include measurement of thymidine incorporation and uptake, of labelling and mitotic indices, and of DNA histograms by flow cytometry. Within 24 h RA (2 X 10-5 M) alone caused a short-lasting inhibition of DNA synthesis; later a decrease of cells in S phase and a steady descending mitotic activity were observed. On combined treatment with RA and TPA (10-8 M), the latter seems to dominate RA in two instances: (1) the transient G2 blockage due to TPA is seen as the earliest effect; however, the cultures do not seem to recover as well if RA is also present; (2) the TPA-induced GI blockage appears to be effective but less pronounced in the presence of both chemicals. Where the third typical TPA-induced effect is concerned, however, both compounds seem to act to a comparable degree in the same time frame; namely by an initial inhibition of DNA synthesis which thus might be a point of critical interference if promoter and modifier age given together.

Complete remission of idiopathic pure red cell aplasia. Case reports

Two patients with pure red cell aplasia of undetermined aetiology are in sustained, complete remission after immunosuppressive therapy. In the first, short-term supplementary plasmapheresis was used during initial chemotherapy, and in the second, anabolic androgens were administered. In both patients haematopoietic recovery was temporally related to the withdrawal of the cyclophosphamide used to cause immunosuppression in the patients over a 4- and 6-month period respectively.

"It's all right if kids can't read"

Our title comes from a feature article that appeared in the Los Angeles Times last fall. Picked up by newspapers nationwide, the story quoted Dr. Richards, who is director of the Kaiser-Permanente Learning Disability Clinic in San Diego with such statements as "Admit it, some people just can't read," "It's like a physical handicap for some kids, a code they'll never break," and "There comes a time to give up trying to teach some of them to read and start letting them live around it." Though generally pessimistic, there were statements made to suggest a concerned, humanistic, yet pragmatic professional. Examples, "Let's not say a child is a failure just because he can't do one thing," or "It's OK if a kid feels all right about himself even if he can't read."

I thought it important that Dr. Richards should have the chance to explain himself to the profession and, therefore, have provided him the opportunity to elaborate his views in an in-depth interview with the Journal of Learning Disabilities. G.M.S.

Responses of synchronized HeLa cells to the tumor-promoting phorbol ester 12-O-tetradecanoylphorbol-13-acetate as evaluated by flow cytometry

A flow cytometric study was carried out on the effects of tumor-promoting 12-O-tetradecanoylphorbol-13-acetate (TPA; 10(-8) M) on HeLa cells synchronized by amethopterin for DNA synthesis. Cells treated with TPA at the time of release from the amethopterin block showed a delayed passage through S phase and partially through G2 in their immediate life span as measured 24 hr after release. This late G2 delay was not observed when TPA was added to cells during late S or G2 phase. In this case, however, a direct inhibition of cells in G2 became evident as observed about 15 hr after release from block. None of these effects was caused by the nonpromoting 4-O-methyl-12-O-tetradecanoylphorbol-13-acetate (10(-6) M). These data support observations obtained with asynchronous cultures. The TPA effects resemble those reported after X-irradiation of cell cultures.

Early effects of the tumor-promoting phorbol ester 12-O-tetradecanoylphorbol-13-acetate on the cell cycle traverse of asynchronous HeLa cells

Within 24 hr after incubation of synchronous HeLa cell cultures with small nontoxic doses of the tumor promoter 12-O-tetradecanoylphorbol-13-acetate (TPA; 10(-7) or 10(-8) M), a variety of transient alterations in the cell cycle traverse was detected by different techniques. The measurement of thymidine incorporation rates into DNA, of labeling and mitotic indices, and of flow cytometry revealed (a) an inhibition of cells in G1 shortly prior to their entering S phase, (b) a reduced rate of DNA synthesis and a delayed passage of cells through S phase which were in this phase on addition of TPA, (c) a delayed passage through G2 of a portion of cells which were somewhere in the first half of the S phase on addition of TPA, and (d) an instant but short-lasting blockage in G2 immediately before mitosis. The effects of TPA are reminiscent of published results on X-irradiated cell cultures. None of these effects was noticed with the hyperplasiogenic but nonpromoting phorbol ester 4-O-methyl-12-O-tetradecanoylphorbol-13-acetate (10(-6) M). The data were confirmed by experiments with synchronized HeLa cells as described in an accompanying paper.

Carcinoid heart disease: eight-year survival following tricuspid valve replacement and pulmonary valvotomy

A 34-year-old man with carcinoid heart disease underwent tricuspid valve replacement and pulmonary valvotomy with enlargement of the right ventricular outflow tract in October, 1972. He has no cardiac symptoms eight years after operation. Only four previous successful valve replacements in patients with this condition have been reported.

Tumor promoter TPA mimics irradiation effects on the cell cycle of HeLa cells

When asynchronous and synchronous HeLa cells were incubated with small doses (10(-7) M) of tumor promoter 12 O-tetradecanoylphorbol-13-acetate (TPA), a variety of transient alterations in the replication cycle were detected within 24 hours by the use of independent methods. Especially, a delayed passage through the S phase and influences on the G2 phase resemble x-ray irradiation effects on cell cultures. None of these alterations was observed with the hyperplasiogenic but nonpromoting 4-O-methyl-TPA.

The classification, investigation and treatment of the anaemic patient

Anaemia is one of the commonest symptoms reported to medical practitioners by their patients. A combined morphological and functional approach to classification is preferred, but the crucial point is the need to establish the cause of the symptom before selecting any form of therapy. Treatment before making an accurate diagnosis, especially the use of haematinics other than those specifically needed, may be dangerous and cannot be too strongly deprecated.

Effects of a zinc citrate mouthwash on dental plaque and salivary bacteria

A double-blind crossover trial was carried out to assess the effect of zinc citrate on plaque accumulation in vivo and to measure total salivary aerobes and anaerobes both during the trial and throughout the day following a single rinse. When compared to the placebo, zinc citrate significantly reduced the plaque accumulation in the subjects. However, the mean reduction was small and of questionable clinical importance. A progressive increase in plaque was observed throughout both active and placebo 7-day rinsing periods. There was no significant reduction in salivary bacterial counts either during the crossover study or during the day following a single rinse with zinc citrate.

Primary culture of human mammary epithelial cells embedded in collagen gels

Human mammary epithelial cells were dissociatd from mastectomy tissues. The contaminating fibroblasts were removed by the use of Percoll density-gradient centrifugation, which utilizes the difference in buoyant densities between epithelial cells and fibroblasts. A preparation highly enriched for mammary epithelial cells ws then embedded in collagen gel and cultured in Ham's F12 medium containing 12.5% horse serum, 2.5% fetal calf serum, 0.1 microgram cholera toxin/ml, an extract prepared from human male urine (L microgram protein/ml), and a hormone combination of 10 microgram insulin/ml, 10 microgram human placental lactogen/ml, 1 microgram aldosterone/ml, and 0.5 microgram hydrocortisone/ml. Sustained growth leading to an increase of tenfold to thirtyfold in cell number over the initial value was accomplished in primary culture, and this growth was maintained even after passage to secondary culture. Deletion of either the urine extract or the hormone combination resulted in less than optimal growth. Subsequent studies showed that hydrocortisone alone could replace the hormone combination. In addition, urine extract could be replaced by extracts prepared from human kidneys or brains. The collagen gel system provies a reproducible and consistent method for sustained three-dimensional growth of mammary epithelial cells from human breast tissue in primary as well as passaged cultures.

Growth factor- and cyclic nucleotide-induced proliferation of normal and malignant mammary epithelial cells in primary culture

Sustained growth of normal mouse mammary epithelial cells in primary culture, leading to an increase in cell number, in response to growth factors [epidermal growth factor (EGF) and fibroblast growth factor (FGF)] or cholera toxin has been achieved by embedding the cells inside collagen cells. Inclusion of agents known to increase the level of cellular cAMP have been found to be favorable for mammary epithelial cell proliferation. Cholera toxin is by far the best of all of the agents tested (prostaglandins E1 and E2, isoproterenol, theophylline, and dibutyryl cAMP). When growth factors (EGF or FGF) are added with cholera toxin, a synergistic effect resulting in a response much greater than with either of them alone is seen. This synergism was best seen in normal mammary epithelial cells from nonpregnant mice. The extent of this synergistic effect was found to be less in normal cells from pregnant mice, suggesting that these cells may be less responsive to EGF during pregnancy. Tumor cells were found to be rather inconsistent in their responses to EGF and cholera toxin, ranging from a minimal response, similar to that of normal cells from pregnant animals, to a maximal response, similar to that of normal cells from nonpregnant animals.

Prospective study of fetal heart rate and rhythm patterns

The fetal heart beat, detected by ultrasound, was recorded for five minutes from 934 antenatal women--266 at 30 to 35 weeks' gestation and 718 at 36 to 41 weeks. Episodes of bradycardia < 100/minute ranging from 5-30 seconds' duration occurred in 3 (1.1%) of the former and in 9 (1.3%) of the latter group. Tachycardia > 180/minute ranging from 30-90 seconds' duration occurred in 1 (0.4%) of the former and in 4 (0.6%) of the latter. Premature beats were not detected between 30 and 35 weeks, but occurred in 12 (1.7%) of 720 at 36 to 41 weeks' gestation. 50 subjects were monitored at both 30 and 35 weeks and 36 to 41 weeks' gestation and in one woman premature beats were present in the latter but not in the former recording. The incidence (1.7% of premature beats in the fetus at 36 to 41 weeks' gestation was similar to that in the healthy neonate (0.8%). Recordings of arrhythmias or rates outside the range 100-180/minute were replayed through a standard antepartum fetal heart rate monitor. The monitor failed to detect premature beats, 2 to 4 episodes of tachycardia > 180/minute, and 9 of 12 episodes of bradycardia < 100/minute, stressing its unreliability for detecting rapidly changing rates.

Primary culture of mouse mammary tumor epithelial cells embedded in collagen gels

Mammary tumor epithelial cells from BALB/cfC3H mice were dispersely embedded inside the collagen gels in Ham's F-12 medium containing horse serum. A sustained cell growth leading to a 5- to 10-fold increase in cell number over initial level was observed in less than 2 weeks. The extent of this growth was found to be dependent on serum concentration. However, addition of various protein and steroid hormones, both singly and in combination, to low-serum-containing medium failed to achieve a comparable level of growth to that promoted by higher serum concentration. Mammary tumor cells can now be consistently propagated in primary culture.