[Posterior chamber intraocular lens implantation in the absence of posterior capsular support]

The authors retrospectively studied the clinical records of 15 eyes without posterior capsular support receiving transscleral ciliary sulcus fixation of posterior chamber intraocular lenses. Postoperative followup period range from 2 weeks to 8 months, an average of 2.2 months. Postoperative visual acuity improved in all patients, 20% of which had 0.6 or better and 40%-between 0.2 and 0.5. Lens rotation was the primary complication and accounted for poor acuity in some cases. The results indicate that ciliary sulcus fixation in the absence of posterior capsular support appears to be safe and effective and may represent a significant advance in anterior segment surgery.

Genetic transfer of a nonpeptide antagonist binding site to a previously unresponsive angiotensin receptor

Mutational analysis based on the pharmacological differences between mammalian and amphibian angiotensin II receptors (AT receptors) previously identified 7 aa residues located in transmembrane domains (TMs) III (Val-108), IV (Ala-163), V (Pro-192, Thr-198), VI (Ser-252), and VII (Leu-300, Phe-301) of the rat AT receptor type 1b (rAT1b receptor) that significantly influenced binding of the nonpeptide antagonist Losartan. Further studies have shown that an additional 6 residues in the rAT1b receptor TMs II (Ala-73), III (Ser-109, Ala-114, Ser-115), VI (Phe-248), and VII (Asn-295) are important in Losartan binding. The 13 residues required for Losartan binding in the mammalian receptor were exchanged for the corresponding amino acids in the Xenopus AT receptor type a (xATa receptor) to generate a mutant amphibian receptor that bound Losartan with the same affinity as the rAT1b receptor (Losartan IC50 values: rAT1b, 2.2 +/- 0.2 nM: xATa, > 50 microM; mutant, 2.0 +/- 0.1 nM). To our knowledge, this is the first report of a gain-of-function mutant in which the residues crucial to formation of a ligand binding site in a mammalian peptide hormone receptor were transferred to a previously unresponsive receptor by site-directed mutagenesis. Ala substitutions and comparison of mammalian and amphibian combinatorial mutants indicated that TM III in the rAT1b receptor plays a key role in Losartan binding. Identification of residues involved in nonpeptide ligand binding will facilitate studies aimed at elucidating the chemical basis for ligand recognition in the AT receptor and peptide hormone receptors in general.

Association of body mass index and body fat distribution with risk of lung cancer in older women

Obesity has been associated with an increased risk of cancer at a number of sites. A notable exception appears to be lung cancer, for which several studies suggest a modest inverse association. However, cigarette smoking is directly associated with lung cancer and inversely associated with body mass index. To investigate the hypothesis that body mass index is associated with lung cancer independent of cigarette smoking, the authors analyzed data from a prospective cohort study of 41,837 Iowa women aged 55-69 years at baseline in 1986. In addition, they examined whether central adiposity (high waist/hip ratio) was associated with lung cancer incidence. Through 1992 (6 years of follow-up), 233 cases of lung cancer were identified through the State Health Registry of Iowa. The body mass index at several ages was calculated from self-reports of height at baseline and weights at ages 18, 30, 40, and 50 years and at baseline. Current and former smokers generally had lower mean body mass indices than did nonsmokers at all ages except 18 years. Cases generally had lower body mass indices than did noncases at all ages except 18 and 30 years but, among current smokers, cases had higher mean body mass indices than did noncases at all ages except baseline, although the differences were not statistically significant. An apparent positive association of a high waist/hip ratio with lung cancer in the total cohort was found to be primarily accounted for by a higher waist/hip ratio in current and former smokers. When stratified by smoking status and adjusted for other risk factors, including age and pack-years of smoking, the body mass index at baseline, body mass index at age 50 years, and waist/hip ratio were not associated with lung cancer. The results of multivariate analyses suggest that the inverse association of body mass index with lung cancer can be explained by smoking status and that the positive association of waist/hip ratio with lung cancer can be explained by pack-years of smoking.

Dietary intake of energy and animal foods and endometrial cancer incidence. The Iowa women's health study

To assess the relations of dietary intake of energy and animal foods to endometrial cancer risk, dietary analyses were performed using data from a prospective cohort study of over 23,000 postmenopausal Iowa women who responded to a mailed questionnaire in 1986 and were followed through the end of 1992 for cancer incidence and total mortality. Usual intakes of 127 food items were measured by a semiquantitative food frequency questionnaire. After 7 years of follow-up, 216 incident endometrial cancer cases had been ascertained. There was no statistically significant association of dietary intake of energy and most animal foods with endometrial cancer incidence over the 7-year follow-up period. Stratified analyses, however, suggested that intake of energy from plant foods may be inversely associated with endometrial cancer risk in the latter years of follow-up (trend test, p = 0.03), while high intake of energy and foods from animal sources related to slightly, but not statistically significantly, elevated risks of this cancer in the earlier years of follow-up. The only significant dose-response relation observed in food group analyses was for processed meat and fish, for which a significant 50% excess risk of endometrial cancer was found among women in the highest versus the lowest tertile of intake. This study suggests that dietary intake of energy and most animal foods is not related to or is only weakly related to the risk of endometrial cancer among postmenopausal US women.

Hormonal replacement therapy and morbidity and mortality in a prospective study of postmenopausal women

We assessed the association of hormonal replacement therapy with mortality and incidence of multiple diseases in over 40,000 postmenopausal women followed for 6 years as part of the Iowa Women's Health Study. Compared with women who never used hormone replacement therapy, current users had multivariate adjusted relative risks (RR) as follows: total mortality (RR = 0.78; 95% confidence interval [CI] = 0.65, 0.94), coronary heart disease mortality (RR = 0.74; 95% CI = 0.48, 1.12), endometrial cancer incidence (RR = 4.3; 95% CI = 2.7, 6.9), breast cancer incidence (RR = 1.23; 95% CI = 0.99, 1.55), colon cancer incidence (RR = 0.72; 95% CI = 0.46, 1.12), and hip fracture incidence (RR = 0.53; 95% CI = 0.31, 0.91).

Excimer laser photorefractive keratectomy for myopia in China. A report of 750 eyes with a 6-month follow-up

A total of 750 six-month follow-up records of myopia treated with excimer laser photorefractive keratectomy (PRK) were analyzed. By 6 months, in group 1 (up to -6.00D, 587 eyes), uncorrected visual acuity was improved to 20/20 or better in 86.7% of treated eyes and 95.4% fell into the range of refraction of +/- 1.00D. In group 2 (-6.25D to -11.00D, 163 eyes), 74.5% of treated eyes had uncorrected visual acuity of 20/20 or better and 89.4% of the eyes were within +/- 1.00D. The designed predictability of the two groups was the same (P > 0.1). The refractive stability from 3 to 6 months between the two groups was not statistically different, and no severe complications were observed in these two groups. The excimer laser PRK for correcting myopia up to -11.00D appears to be effective, predictable, stable and safe in this study. The ideal outcome may result from the precise ablation quality of excimer laser, its computerized surgical manipulation and an appropriate postoperative management including detection of refractive indices by corneal topography and modulation by steroid.

An analysis on follow-up results of photoreactive keratectomy for treatment of myopia

A prospective study of excimer laser photorefractive keratectomy (PRK) was performed with the aim of correcting a range of myopic errors between -1.00 and -10.00 diopters on 422 myopic eyes that were followed for more than one year. At postoperative one year, 91.4% of the eyes had uncorrected visual acuity of 20/20 or better, and 97.4% were within +/- 1.00 diopter of the desired emmetropia, and the corneal haze disappeared in most of the eyes. Elevated intraocular pressures were observed in 20.4% of the eyes. The decrease of one line of the best corrected visual acuity occurred in 7.6% and of two lines in 0.5% of the eyes. We think that the excimer laser PRK is a very predictable, safe, stable, and effective method to correct myopia up to -10.00 D, and longer follow-up will be necessary.

Endocrine, gonadal and behavioral responses of male crucian carp to the hormonal pheromone 17 alpha,20 beta-dihydroxy-4-pregnen-3-one

The olfactory-mediated responses to the sex hormone 17 alpha,20 beta-dihydroxy-4-pregnen-3-one (17 alpha,20 beta-P) were studied in spermiated and regressed male crucian carp (Carassius carassius L.). The position and spontaneous locomotor activity of single male crucian carp were continuously recorded in an artificial stream. 17 alpha,20 beta-P (final concentration 10(-11) M) was supplied to one half and its ethanol carrier to the other half of the test area. Milt volume and gonadotropin (GtH-II) concentration in the plasma were also measured. The smell of 17 alpha,20 beta-P significantly increased both the GtH-II concentration in the plasma and the volume of strippable milt in spermiated crucian carp. Behaviorally, the side of the test area scented with 17 alpha,20 beta-P was significantly avoided by spermiated males. None of the described effects of 17 alpha,20 beta-P on spermiated males were observed for the regressed crucian carp. In view of the lack of response from regressed crucian carp we suggest that the observed avoidance behavior of 17 alpha,20 beta-P by spermiated males is a relevant reaction for spawning male crucian carp. The results are well in accordance with responses obtained in the closely related goldfish and gives strong support that the wild male crucian carp use the 17 alpha,20 beta-P signal from the females to prepare for the coming spawning.

[Glucocorticoid-induced ocular hypertension after photorefractive keratectomy]

1,628 myopic eyes were performed with excimer laser photorefractive keratectomy (PRK) and 1% prednisolon eyedrops was used for postoperative regime. All patients after PRK were followed 2-14 months, 9.89% had an intraocular pressure of more than 2.933 kPa (22mmHg) at first month and 15.05% at third month. Male patients showed higher response to glucocorticoid than female patients. There was no correlation between elevations of intraocular pressue and refractive powers.

Behavioural and endocrinological responses of mature male goldfish to the sex pheromone 17alpha,20beta-dihydroxy-4-pregnen-3-one in the water

The behavioural response of spermiated male goldfish to the sex pheromone 17alpha,20ss-dihydroxy-4-pregnen-3-one (17alpha,20ss-P) in the ambient water was measured using a computerized video-image analysis system. The position and spontaneous locomotor activity of single spermiated male goldfish were continuously recorded in an artificial stream. 17alpha,20ss-P (final concentration 10(-11) mol l-1) was supplied to one half and its ethanol carrier to the other half of the test area. The results showed that the fish spent significantly less time in water scented with 17alpha,20ss-P than in control water. Moreover, both the spontaneous locomotor activity and the gonadotropin II concentration in the plasma increased significantly because of contact with 17alpha,20ss-P in the ambient water. The swimming speed was unchanged, whether the fish resided in the 17alpha,20ss-P section or in the section without 17alpha,20ss-P added. In view of the complex dual hormone-pheromone system in goldfish, the possibility of an additional function of 17alpha,20ss-P is discussed. Because the release of the pheromone 17alpha,20ss-P occurs before ovulation and the level then drops drastically, we suggest that the avoidance reaction observed allows the sexually mature male to avoid misdirected courting of non-ovulated females and thus to continue its search for an ovulated female.

Cloning and characterization of a calcium channel alpha 1 subunit from Drosophila melanogaster with similarity to the rat brain type D isoform

We report the complete sequence of a calcium channel alpha 1 subunit cDNA cloned from a Drosophila head cDNA library. This cDNA encodes a deduced protein containing 2516 amino acids with a predicted molecular weight of 276,493. The deduced protein shares many features with vertebrate homologs, including four repeat structures, each containing six transmembrane domains, a conserved ion selectivity filter region between transmembrane domains 5 and 6, and an EF hand in the carboxy tail. The Drosophila subunit has unusually long initial amino and terminal carboxy tails. The region corresponding to the last transmembrane domain (IVS6) and the adjacent cytoplasmic domain has been postulated to form a phenylalkylamine-binding site in vertebrate calcium channels. This region is conserved in the Drosophila sequence, while domains thought to be involved in dihydropyridine binding show numerous changes. The Drosophila subunit exhibits 78.3% sequence similarity to the rat brain type D calcium channel alpha 1 subunit, and so has been designated as a Drosophila melanogaster calcium channel alpha 1 type D subunit (Dmca1D). In situ hybridization shows that Dmca1D is highly expressed in the embryonic nervous system. Northern analysis shows that Dmca1D cDNA hybridizes to three size classes of mRNA (9.5, 10.2, and 12.5 kb) in heads, but only two classes (9.5 and 12.5 kb) in bodies and legs. PCR analysis suggests that the Dmca1D message undergoes alternative splicing with more heterogeneity appearing in head and embryonic extracts than in bodies and legs.

[Photorefractive keratectomy for myopia: 6 month results]

The argon fluoride excimer laser is able to ablate the superficial cornea and to correct refractive problems. Photorefractive keratectomy (PRK) was performed on 103 myopic eyes ranging from -0.75D to -6.00D. We prospectively evaluated visual and refractive results that were followed for more than 6 months. Uncorrected visual acuity of 1.0 or better was achieved in 88.35%. The difference between attempted and achieved refractive correction was within +/- 1.00D in 94.17%. 10 eyes (9.71%) had trace to mild subepithelial hare and 19 eyes (18.45%) had loss of one line of best spectacle corrected visual acuity. The excimer laser PRK appears to be a predictable and effective method to correct myopia under -6.00D.

Infant breastfeeding and the risk of childhood lymphoma and leukaemia

BACKGROUND

A protective effect of breastfeeding on childhood lymphoma has been indicated but supportive evidence is limited.

METHOD

Data from a population-based case-control study of childhood cancer in Shanghai, including 82 lymphoma cases and 159 acute leukaemia cases and their age- and sex-matched community controls, were analysed.

RESULTS

After adjustment for potentially confounding variables, a slight, although non-significant, reduction in risk of lymphoma was observed among children who were breastfed as infants versus those who were not (odds ratio [OR] = 0.69; 95% CI: 0.3-1.7). The reduction was somewhat greater for children who had been breastfed longer and appeared to pertain primarily to Hodgkin's disease and to cases diagnosed before the age of 6 years. As expected, there was no reduction in risk of acute leukaemia associated with breastfeeding.

CONCLUSIONS

Although providing neither strong support for nor refuting the study hypothesis, these data suggest that if breastfeeding does reduce the risk of lymphoma, its protective effect among Chinese children is likely modest in magnitude and concentrated in certain subgroups defined by length of breastfeeding, age at diagnosis and histological subtype of cancer.

Familial clustering of breast and prostate cancers and risk of postmenopausal breast cancer

BACKGROUND

Previous studies have suggested that cancers of the breast and prostate cluster in families and that the presence of both diseases in a family may be associated with increased risk of breast cancer.

PURPOSE

Our purpose was to evaluate whether 1) prostate cancer aggregates in families with postmenopausal breast cancer, 2) families with cancers of the breast and prostate are the same ones as families with cancers of the breast and ovary, and 3) a family history of prostate cancer is associated with increased risk of postmenopausal breast cancer.

METHODS

We analyzed data from a large prospective cohort study of Iowa women that were (at baseline) aged 55-69 years in 1986. At the third follow-up survey in 1992, self-reported data on family history of breast, ovarian, and prostate cancers in parents and siblings were provided by 30,883 women. Additional information was collected to ascertain whether the age-of-onset of breast cancer in mothers or sisters was before or after the age of 45 years. Cancer occurrence was documented using the State Health Registry of Iowa.

RESULTS

History of prostate cancer in their father or a brother was reported by 3384 (11.0%) of the women, and a total of 4090 women (13.2%) reported breast cancer in their mother or a sister. A positive family history of both cancers was reported by 556 women, significantly (two-sided P < .001) greater than the 457 women expected if the family histories were independent. The aggregation of breast, prostate, and ovarian cancers was reported by 22 participants, greater than the 2.7 expected (two-sided P < .0001). During 6 years of follow-up, 578 breast cancers were identified in the cohort at risk. Compared with women without a family history of either cancer, women with a family history of breast cancer had a relative risk (RR) of 1.37 (95% confidence interval [CI] = 1.06-1.79) if the affected relative had onset after the age of 45 years, and an RR of 1.71 (95% CI = 1.13-2.61) if the affected relative had onset at or before the age of 45. A family history of prostate cancer in the absence of a family history of breast cancer was associated with an RR of 1.19 (95% CI = .90-1.56). However, a family history of both breast and prostate cancers was associated with RRs of 2.06 (95% CI = 1.23-3.45) and 2.35 (95% CI = .97-5.67) for breast cancer onset in relatives of greater than 45 and less than or equal to 45 years, respectively.

CONCLUSIONS

These observations are concordant with recent reports that suggest a shared familial risk (inherited or environmental) for these hormone-dependent malignancies.

In vivo actions of a gonadotropin-releasing hormone (GnRH) antagonist on gonadotropin-II and growth hormone secretion in goldfish, Carassius auratus

In our previous in vitro studies, [Ac-delta 3-Pro1, 4FD-Phe2, D-Trp3,6]-mGnRH (analog E) suppressed both gonadotropin-II (GTH-II) and growth hormone (GH) release stimulated by sGnRH and cGnRH-II. In the present study analog E significantly inhibited the increases in plasma GTH-II levels stimulated by sGnRH in sexually mature female and sexually recrudescent goldfish. Treatment of goldfish with alpha-methyl-p-tyrosin methyl ester (alpha-MPT) inhibits dopamine synthesis and abolishes the inhibitory actions of dopamine on GTH-II release, resulting in a potentiation of the GTH-II response to sGnRH. Following alpha-MPT pretreatment, analog E significantly reduced basal plasma GTH-II levels, and suppressed both sGnRH and cGnRH-II actions on GTH-II release. Analog E also inhibited the increase in plasma GTH-II levels in sexually mature male goldfish exposed to the female sexual pheromone, 17 alpha, 20 beta-dihydroxy-4-pregnen-3-one (17 alpha 20 beta-P), demonstrating that the increase in plasma GTH-II levels is due to release of endogenous GnRH. Analog E significantly inhibited the increases in plasma GH levels stimulated by treatment with sGnRH. Implantation of estradiol pellets increases basal plasma GH levels and increases the GH responsiveness to sGnRH in sexually recrudescent goldfish; analog E also suppressed the increase in plasma GH levels stimulated by injection of sGnRH in estradiol-treated fish. Analog E suppressed basal GTH-II and GH levels in fish that were unhandled prior to injection; however, analog E was not effective in reducing basal plasma GTH-II or GH levels in experiments in which the fish were blood sampled or subjected to some experimental manipulation prior to injection of analog E. Analog E also suppressed basal levels of GTH-II in alpha-MPT-treated fish, suggesting that stress inhibition of GTH-II release may be mediated by the dopaminergic system. In summary, the results demonstrate that (i) analog E can suppress the actions of exogenous sGnRH and cGnRH-II on GTH-II and GH release in vivo, (ii) the GnRH system mediates, at least in part, the plasma GTH-II response in sexually mature male goldfish following exposure to the female sexual pheromone 17 alpha 20 beta-P, and (iii) endogenous GnRH peptides are important in the regulation of basal plasma levels of GTH-II as well as GH, particularly in low stress conditions.

Tissue distribution and elimination of indium in male Fischer 344 rats following oral and intratracheal administration of indium phosphide

The use of indium phosphide (InP) in the semiconductor industry has raised concerns about potential occupational exposure. The tissue distribution and elimination of indium were investigated in adult male Fischer 344 rats following either a single or 14 consecutive daily oral doses, or following an intratracheal instillation of InP (10 mg/kg). The concentrations of indium ions in blood, urine, feces, and tissues were quantified either using direct acid digestion followed by electrothermal atomic absorption spectrophotometry (ET-AAS) or using an extraction method with methyltricapryl ammonium ions to remove indium from the matrix followed by ET-AAS. Indium was poorly absorbed from the gastrointestinal tract in both single and multiple oral dose studies. Upon its absorption, indium was relatively evenly distributed among the major organs such as liver, kidney, lung, spleen, and testes. By 96 h after oral dose treatment, less than 0.11% of the dose of indium was recovered from tissues in the single- or multiple-dose experiment. At 96 h, retention of indium in the body was about 0.36% of the dose (except for lung) following intratracheal instillation of InP. Following oral dose administration, the majority of indium was recovered from the gastrointestinal tract and its contents. The high recovery of indium (73% of the dose) in the feces after intratracheal instillation presumably reflects mucociliary clearance and/or biliary excretion of indium. Urinary indium accounted only for 0.08-0.23% of the dose during a 240-h collection period in both single- and multiple-dose studies. It seems that fecal excretion serves as the major route for indium elimination, and this results from poor absorption. Because of the poor absorption of indium following multiple oral doses or intratracheal instillation of InP, it seems unlikely that indium will accumulate in the body following InP exposure.

Transposon-induced mutants of Listeria monocytogenes incapable of growth at low temperature (4 degrees C)

Transposon mutagenesis was used to pursue the molecular basis of cold resistance in Listeria and its possible involvement in pathogenesis. We have generated transposon-induced mutants of Listeria monocytogenes which were unable to grow at 4 degrees C but grew at 8 degrees C, 22 degrees C and 37 degrees C. The transposon was localized in the same 1.8-kb EcoRI fragment in two independently derived mutants. Mutants which carried single transposon insertions had normal hemolytic activity, motility and invasion of cultured fibroblasts. These results indicate that in L. monocytogenes cold sensitivity can be single transposon insertions and that loss of cold resistance may not interfere with other phenotypes, including invasion in a cell culture model.

[A controlled study of chemiluminescent enzyme immunoassay for the measurement of estrogen receptor in tissue of gynecological neoplasms]

In this study, chemiluminescent enzyme immunoassay (CLEIA) has been developed for the measurement of estrogen receptor (ER) in 34 gynecological oncological tissues from 15 cases of endometrial carcinoma, 15 cases of ovarian tumors and 4 cases of other gynecological tumors. The accuracy, specificity and sensitivity of CLEIA for ER were compared with that of dextran-coated charcoal (DCC) and enzyme immunoassay (EIA).

RESULTS

(1) the standard curve of ER-CLEIA showed a significant linear correlation between the luminosity and ER concentration (r = 0.9786, P < 0.001); (2) The results of CLEIA and that of the other two methods were compared; the correlation coefficients were > 0.8 and their corresponding rates were > 90%; (3) the positive rate of ER determined by these three methods showed no significant differences, however, the mean value of ER-CLEIA was the highest among them. It is concluded that the CLEIA has a higher sensitivity than that of the other two methods for the measurement of ER.

Dietary cholesterol, fat, and lung cancer incidence among older women: the Iowa Women's Health Study (United States)

To test the hypothesis that a high intake of dietary cholesterol and fat is associated with elevated risks of lung cancer, we analyzed data from a population-based, prospective, cohort study conducted among 41,837 postmenopausal Iowa (United States) women who completed, in 1986, a comprehensive mailed questionnaire including information on usual intake of 127 food items. All cohort members were followed for cancer incidence through the statewide cancer registry. By 1991, after six years of follow-up, 272 incident lung-cancer cases were identified. After controlling for total energy intake and other confounding factors, dietary cholesterol, total fat, and animal fat were unrelated to lung cancer risk. Intake in the upper three quartiles of plant-derived fat, however, was related to a 30 to 40 percent lower incidence of lung cancer, comparative with those in the lowest quartile, with more pronounced reduction in risk observed among smokers (relative risk = 0.6, 95 percent confidence interval = 0.4-0.9). This prospective cohort study suggests that high intake of fat of plant origin may be associated with reduced risk of lung cancer, while dietary cholesterol and animal fat intake is unrelated to the etiology of this malignancy in postmenopausal women.

Diagnostic X-ray and ultrasound exposure and risk of childhood cancer

In a population-based case-control study of 642 childhood cancer cases and the same number of matched controls in Shanghai, China, we evaluated the relationship between diagnostic X-ray (preconception, pre- and post-natal) and antenatal ultrasound exposure and the subsequent risk of developing three major types of childhood cancer (acute leukaemia, lymphoma and brain tumours) and all childhood neoplasms combined. Consistent with previous studies, prenatal X-ray exposure was found to be associated with an 80% increased risk of childhood cancers, although the estimation was based on 4% and 2% exposed cases and controls and was only marginally statistically significant (P = 0.08). Post-natal X-ray exposure was also linked with a small elevation in the risk of all cancers and the major categories of malignancies in children. Little evidence, however, was found to relate parental preconception X-ray exposure with the subsequent cancer risk in offspring, regardless of the exposure window and the anatomical site of X-ray exposures. This study adds further to the growing literature indicating that antenatal ultrasound exposure is probably not associated with an increased risk of childhood cancer.

[Expression of cDNA RA538 induces terminal differentiation and apoptosis of its parental malignant cell line in vitro]

A full-length cDNA (RA538) was isolated from human esophageal cancer cell line EC8712 after retinoic acid treatment. An expression vector of this cDNA (pRA538) was cotransfected with the neo gene (pDORneo) into parental cancer cell line EC8712. The cell colonies obtained after selection in G418-containing culture medium showed very poor growth, reduced (by 68%-76%) 3H-TdR uptake and morphological changes characteristic of terminal differentiation and programmed cell death (apoptosis). In situ hybridization with RA538 probes revealed expression of mRNA of RA538 in the cytoplasm of the transfected cells. The cells transfected solely with pDORneo after G418 selection showed normal growth pattern and no RA538 expression. However, none of the control cells EC8712 survived the G418 selection. Thus the expression of cDNA RA538 has a similar effect on the esophageal cancer cell EC8712 as the retinoic acid does.

Diet, serum markers and breast cancer mortality in China

This county-based correlation study examined associations of breast cancer mortality with dietary habits and certain serum biochemical markers, utilizing data collected from an ecological survey in 65 Chinese rural counties. Univariate correlation and multivariate regression analysis showed that consumption of animal foods, including eggs, fish and meat, was positively linked to county-wide mortality rates of breast cancer in Chinese women. No clear associations between breast cancer mortality rates and consumption of green vegetables, carrots and fruits were observed in this study. A modest inverse correlation between serum vitamin C levels and breast cancer mortality was observed, while selenium levels were positively related to the mortality rates. Positive correlations for serum ferritin and hemoglobin were found, in agreement with recent reports of an elevated cancer risk with increased body iron stores. Limitations of these ecological data preclude causal inferences, but the findings provide clues to breast cancer risk and protective factors in a low incidence area of the world.