Convergence of progesterone with growth factor and cytokine signaling in breast cancer. Progesterone receptors regulate signal transducers and activators of transcription expression and activity

STATS (signal transducers and activators of transcription) are latent transcription factors activated in the cytoplasm by diverse cell surface signaling molecules. Like progesterone receptors (PR), Stat5a and 5b are required for normal mammary gland growth and differentiation. These two proteins are up-regulated during pregnancy, a period dominated by high levels of progesterone. We now show that progestin treatment of breast cancer cells regulates Stat5a and 5b, Stat3, and Stat1 protein levels in a PR-dependent manner. In addition, progestin treatment induces translocation of Stat5 into the nucleus, possibly mediated by the association of PR and Stat5. Last, progesterone pretreatment enhances the phosphorylation of Stat5 on tyrosine 694 induced by epidermal growth factor. Functional data show that progestin pretreatment of breast cancer cells enhances the ability of prolactin to stimulate the transcriptional activity of Stat5 on a beta-casein promoter. Progesterone and epidermal growth factor synergize to control transcription from p21(WAF1) and c-fos promoters. These data demonstrate the convergence of progesterone and growth factor/cytokine signaling pathways at multiple levels, and suggest a mechanism for coordination of PR and Stat5-mediated proliferative and differentiative events in the mammary gland.

Neonatal screening for cystic fibrosis in Wales and the West Midlands: clinical assessment after five years of screening

Screening of the newborn for cystic fibrosis by measurement of immunoreactive trypsin has been undertaken on alternate weeks in Wales and the West Midlands for five years since 1985 to evaluate the possible clinical benefits of early diagnosis. Patients detected by screening and those diagnosed by clinical symptoms alone were assessed annually for differences in clinical, anthropometric, and biochemical variables. Fifty eight infants not considered to be at risk of cystic fibrosis (they did not present with meconium ileus and do not have a sibling with cystic fibrosis) have been detected by screening and they have been compared with 44 children who were diagnosed clinically. This latter group includes nine children whose screening was negative but who were recognised subsequently to have cystic fibrosis. The mean age at diagnosis of the screened group was significantly lower than that of the group diagnosed clinically. Excluding admissions for diagnostic tests for cystic fibrosis, the screened group spent a significantly shorter time in hospital during the first year of life. The results of all other comparisons made between the screened group and those diagnosed clinically were similar up to the age of 4 years.

High sodium intake is associated with increased glucocorticoid production, insulin resistance and metabolic syndrome

OBJECTIVE

High sodium (HS) diet is associated with hypertension (HT) and insulin resistance (IR). We evaluated whether HS diet was associated with a dysregulation of cortisol production and metabolic syndrome (MetS).

PATIENTS AND MEASUREMENTS

We recruited 370 adults (18-85 years, BMI 29·3 ± 4·4 kg/m(2) , 70% women, 72% HT, 61% MetS). HS diet (urinary sodium >150 mEq/day) was observed in 70% of subjects. We measured plasma hormones, lipid profile, urinary free cortisol (UFC) and cortisol tetrahydrometabolites (THM).

RESULTS

Urinary sodium was correlated with UFC (r = +0·45, P < 0·001), cortisol THM (r = +0·41, P < 0·001) and inversely with adiponectin, HDL and aldosterone, after adjusting by age, gender and BMI. Subjects with high, compared with adequate sodium intake (50-149 mEq/day) had higher UFC (P < 0·001), THM (P < 0·001), HOMA-IR (P = 0·04), HT (81% vs 50%, P < 0·001), MetS (69% vs 41%, P < 0·001) and lower adiponectin (P = 0·003). A multivariate predictive model adjusted by confounders showed a high discriminative capacity for MetS (ROC curve 0·878) using four clinical variables: HS intake [OR = 5·6 (CI 2·3-15·3)], HOMA-IR [OR 1·7 (1·3-2·2)] cortisol THM [OR 1·2 (1·1-1·4)] and adiponectin [OR = 0·9 (0·8-0·9)], the latter had a protective effect.

CONCLUSIONS

High sodium diet was associated with increased urinary cortisol and its metabolites. Also, HS diet was associated with HT, insulin resistance, dyslipidaemia and hypoadiponectinaemia, even when adjusting by confounding variables. Further, we observed that high salt intake, IR and higher cortisol metabolites, alone or combined in a clinical simple model, accurately predicted MetS status, suggesting an additive mechanism in obesity-related metabolic disorders.

Stimulation and inhibition of proliferation in the small intestinal crypts of the mouse after in vivo administration of growth factors

The effects of epidermal growth factor (EGF), transforming growth factor alpha (TGF alpha), insulin-like growth factor (IGF) I and II, acidic fibroblast growth factor (FGF), tumour necrosis factor alpha (TNF alpha), macrophage inhibitory protein 1 alpha (MIP-1 alpha) (LD78), and TGF beta-1 on cell proliferation in the crypts of the small intestine of mice were investigated. Various doses and dosing regimens were tested. Three in vivo assays were developed, in each case involving detailed cell positional analysis of methyl tritiated thymidine labelling and mitotic activity. These allowed deductions to be made about the regions of the crypt and hence regions of the proliferative hierarchy (stem cells versus dividing transit cells) that are affected by treatment with growth factors. The assays involved: (1) normal untreated mice (an assay most likely to be effective for detecting inhibitors); (2) mice shortly after whole body irradiation when compensatory proliferation has been endogenously triggered (another assay for inhibitory factors, possibly ones associated specifically with the regenerative process); and (3) mice at late times (96 hours) after irradiation in the regression phase after a proliferative overshoot (an assay designed to detect stimulators). Little effect was seen after treatment with acidic FGF, TNF alpha, or MIP-1 alpha but EGF, IGF-I and II, and TGF alpha can all be seen to exert some stimulatory effects on labelling or mitosis. EGF and IGF-I stimulate both unirradiated mice and 96 hour recipients, while TGF alpha had a greater effect on the 96 hour animals. In all cases, multiple doses were used. TGF beta-1 was an effective inhibitor of proliferation in unirradiated and early regenerating (18 hour) animals. EGF was the most effective of the stimulators, raising the levels of proliferation at all positions in the crypt, but particularly in the upper crypt. IGF-I also exerted its effect predominantly in the upper crypt, while TGF alpha raised proliferation at all cell positions. TGF beta-1 tended to have its strongest inhibitory effects in the lower (stem cell) regions of the crypt.

The temporal and spatial changes in cell proliferation within the irradiated crypts of the murine small intestine

The detailed temporal and spatial changes in the labelling index in crypts of the small intestine of the mouse have been analysed after 8.0 Gy gamma-irradiation. The labelling index was determined for each cell position in the crypts at 34 different times between 3 and 192 h after irradiation. The changes between consecutive time points have been analysed to determine the details of the crypt shrinkage and crypt repopulation phenomena. The following points can be made: (1) There is a dramatic reduction in the overall labelling of the crypt which begins within 3 h and is at its minimum by 15 h postirradiation. Most of this shrinkage can be attributed to continued near-normal emigration of cells from the crypt to the villus while mitosis is reduced or absent, and a possibly premature maturation within the transit population. (2) The labelling index never falls below 34 per cent of control, i.e. many labelled cells persist and continue to replicate their DNA at all times postirradiation. (3) Repopulation begins in the lower regions of the crypt. The first changes are an increase in labelling at cell positions 3-8 that begins at 3 h and reaches a peak at 12 h. There is a second increase in proliferation at the crypt base that begins at about 15 h and reaches a peak at 22-32 h postirradiation. There is a third peak which begins at about 46 h and reaches a peak at 60-70 h. (4) There is a reduction in proliferation at the crypt base that begins at about 72 h postirradiation. (5) The mid and upper crypt population shrinks initially to reach a minimum at about 15 h, after which there is a steady increase to reach a peak at about 72 h. The labelling spreads into the crypt-villus boundary area beginning at about 32 h. There is a reduction of proliferative activity in the mid-crypt region that begins at about 72 h. (6) There is a dramatic overshoot in overall labelling index at 72 h, which involves mainly the upper crypt. This does not revert to normal levels within the 192 h time scale of the present experiments. There is a mild overshoot in labelling at the crypt base at 48-78 h with a return to normal levels thereafter.(ABSTRACT TRUNCATED AT 400 WORDS)

The ixodid tick species attaching to domestic dogs and cats in Great Britain and Ireland

The species of ixodid ticks, attached to dogs and cats presented to veterinary practices in Great Britain and Ireland were identified. Most host animals carried only one tick species with Ixodes ricinus Linné (Acari: Ixodidae) being the most common, identified on 52% of animals, Ixodes hexagonus Leach (Acari: Ixodidae) the second most common (on 39%) and Ixodes canisuga Johnston (Acari: Ixodidae) the third most common (on 11%). A significantly higher proportion of dogs than cats carried I. ricinus, while I. hexagonus was more frequently carried by cats. One animal carried a single specimen of Haemaphysalis punctata Canestrini & Fanzago (Acari: Ixodidae), one carried a Dermacentor reticulatus Fabricius (Acari: Ixodidae) but none carried Rhipicephalus sanguineus Latreille (Acari: Ixodidae). This indicates that the latter two species, vectors of 'exotic' tick-borne diseases, remain at low densities in Great Britain and Ireland. Retrospective information on exposure of the animals to different habitats and geographic regions was collected by questionnaire and subject to contingency table and logistic regression analysis. Woodlands and moorlands were habitats significantly associated with I. ricinus attachment. Exposure to urban parks was significantly associated with I. hexagonus attachment and exposure to boarding kennels and catteries was significantly associated with I. canisuga attachment. Ixodes hexagonus, rather than I. ricinus, was the ixodid tick species most likely to be encountered by urban populations of dogs and cats and, by inference, possibly also humans. The implications of these findings, for the transmission of tick-borne pathogens to dogs, cats and humans are discussed.

An antibiotic policy associated with reduced risk of Clostridium difficile-associated diarrhoea

BACKGROUND

antibiotic-associated diarrhoea caused by Clostridium difficile is increasing in hospitals, and older people are at particular risk.

OBJECTIVE

to establish whether reducing patient exposure to injectable third-generation cephalosporins by substituting alternative antibiotics can produce a cost-effective reduction in the incidence of antibiotic-associated diarrhoea.

DESIGN

we prospectively investigated 2157 patients admitted to the department of elderly medicine in the year before introduction of antibiotic restrictions and 2037 patients admitted in the following year. Patients admitted to other wards, where antibiotic prescribing was unchanged, acted as controls.

SETTING

a 900-bed teaching hospital in Cambridge, UK.

MEASUREMENTS

use and cost of injectable antibiotics prescribed in the department of elderly medicine and the other wards studied; occurrence of C. difficile-associated diarrhoea.

RESULTS

in the wards for older people, consumption of injectable cephalosporins fell by 92% (compared with 8% on other wards) and cases of C. difficile-associated diarrhoea fell from 98 to 45 (cases in other wards rose from 213 to 253; P < 0.001). The Pound Sterling 8062 increase in injectable antibiotic costs on the elderly wards were offset by the release of 1087 wasted bed-days attributable to the 53 fewer cases, with potential savings of Pound Sterling 212,000.

CONCLUSIONS

restricting the consumption of injectable third-generation cephalosporins is a cost-effective method of reducing the incidence of C. difficile-associated diarrhoea.

The differentiation and lineage development of goblet cells in the murine small intestinal crypt: experimental and modelling studies

The objective of this study was to provide a new insight into the origin and lineage development of mucus-producing cells in the small intestinal crypt. For this, new experimental data were obtained from both crypt sections and whole mounts. Model simulation studies were undertaken to investigate which rules are most likely to govern the dynamic cellular development and goblet cell pedigree. We have measured the frequency of mucus-secreting goblet cells (using alcian blue and periodic acid Schiff's stains) at each cell position in the ileal murine crypt. These measurements, made on sections, overestimate the number of goblet cells because of the size and centripetal position of the stained cytoplasm. The correction factor for this overscoring has been measured to be 0.25 by two independent methods. The data suggest that there are about 12 functional goblet cells per crypt many of which retain an ability to divide. We have also determined the labelling index of the crypt goblet cells at each cell position. Spatially, goblet cells exhibit a small degree of clustering in the crypt and show a good mixture with columnar cells. We have adapted our earlier dynamic matrix-based computer stimulation model to take into account goblet cell differentiation. The modelling suggested the following conclusions: firstly, goblet cells do not have their own stem cells but share a common stem cell with the columnar cells; secondly, the goblet lineage differentiates from the transit population two to three generations before the end of the lineage; and thirdly, the decision to switch on goblet properties is stochastic at a specific step in the development of columnar cells.

Morphology of physiologically identified bipolar cells in the retina of the tiger salamander, Ambystoma tigrinum

Intracellular recordings of the light responses of bipolar cells were made in the isolated perfused retina of the larval tiger salamander by microelectrodes filled with a 1% solution of the enzyme horseradish peroxidase (HRP). Two classes of bipolar cell were identified in terms of their responses to luminous spots and annuli centered upon their receptive fields: on-center cells, which depolarized in response to a centered spot and hyperpolarized in response to a concentric annulus, and off-center cells, which responded with the opposite polarities. Physiologically identified cells were labelled with HRP by iontophoretic injection and prepared for light microscopy. Examples of each of the three classes of bipolar cell described in Cajal's study of the amphibian retina were found amongst the labelled cells. The only morphological feature found to correlate with the physiological classification was the stratum at which the axon of the cell arborized in the inner plexiform layer. The axons of on-center cells arborized in the more proximal sublamina b, while those of off-center cells arborized in the more distal sublamina a. This is consistent with earlier findings in the retinae of the cat and the carp.

Studies on the gill of Mytilus edulis: the eu-latero-frontal cirri

Adjacent eu-latero-frontal cirri beat alternately and alternate cirri exhibit metachronous activity. Each cirrus consists of 22─26 pairs of cilia arranged in two parallel but alternating rows. Individual cilia leave the shaft of the cirrus at regular (0.6 μ m) intervals on each side to extend across the intercirrus space. Each cilium, where it bends to leave the cirrus shaft, contains a stiffening rod which extends 1.5 μ m distally as a tapering, hemispherical rod, lying between peripheral fibril 1 and the paired central fibrils. Distal to the bend, the peripheral fibrils are singlets and lack arms. It is concluded that the disposition of this region of the cilium to the cirrus shaft remains more or less constant during both the effective and recovery strokes of the cirrus and this disposition is such that interference between adjacent cirri is minimal while permitting effective filtering of the space between alternate cirri. The mesh of the filter is 0.6 μ m by either 2.4 μ m or 4.8 μ m, the latter depending on the relative positions of adjacent cirri. The pro-latero-frontal cilia may serve to transfer material from the eu-latero-frontal cirri to the frontal cilia of the gill filament.

The palmomental reflex: a useful clinical sign?

The palmomental reflex, an involuntary contraction of the mentalis muscle of the chin caused by stimulation of the thenar eminence, can be tested easily and rapidly. Its presence may alert the clinician to the possibility of cerebral pathology. However, the reflex is often present in normal people and may be absent in disease states. Testing merely for the presence or absence of the reflex therefore lacks both specificity and sensitivity. A strong, sustained, and easily repeatable contraction of the mentalis muscle, which can be elicited by stimulation of areas other than the palm, is more likely to indicate cerebral damage.

Iron nutrition and growth of breast- and formula-fed infants during the first 9 months of life

Feeding of iron (Fe)-fortified (12-15 mg/L) infant formulas is an effective and convenient means to protect infants from Fe deficiency. To study lower levels of Fe fortification of infant formulas (3 or 6 mg/L) compared with those currently in use, we compared Fe intake and Fe nutritional status of three groups of healthy, term infants between 90 and 274 days of age. One group received an Fe-fortified whey-predominant formula (3 mg/L) and the second group received the same formula with a higher Fe level (6 mg/L). A comparison group was breast-fed at least until 274 days of age. All infants received infant foods and cereals according to European Community recommendations. Mean Fe intake of infants fed formula fortified with 3 mg/L was significantly lower at 183 and 274 days of age (p < 0.05) than that of infants fed formula fortified with 6 mg/L. None of the infants fed the formula fortified with 3 mg/L met the recommended daily allowance value (10 mg) for infants between 6 and 12 months of age. Hemoglobin, hematocrit, mean corpuscular volume, free erythrocyte protoporphyrin, and serum ferritin levels were similar in the formula-fed groups; none of the infants had depleted Fe stores (ferritin < 10 micrograms/L) at 183 and 274 days of age. Thirteen percent of breast-fed infants had depleted Fe stores at 183 days of age, but only 3% were depleted at 273 days of age, when Fe-fortified beikost was already part of the diet. No influence of Fe nutritional status was found on zinc and copper nutritional status or on growth.(ABSTRACT TRUNCATED AT 250 WORDS)

Post-awakening cortisol secretion during basic military training

Salivary free cortisol concentrations in the first 30 min after awakening were assessed in 12 healthy army recruits at the beginning, middle and end of an 11-week intensive physical training course. To ensure strict adherence to protocol saliva collection was supervised and collected on each sampling day immediately on waking and again 15 and 30 min later. Self-rated psychological assessments of state levels of stress, arousal and fatigue were performed in the evening of each sampling day. A within-subjects repeated-measures analysis of participants who completed the course (12 of the original 20) showed a significant main effect of cortisol concentration across all three sampling points after awakening (F((2,22))=54.516, p<0.0001) and a significant main effect of weeks into the training course (F((3,33))=4.390, p=0.010). Further analysis of this effect of measurement-week revealed that at weeks 3 and 6 total cortisol secretion estimated by area under the curve was lower (F((3,33))=4.602, p=0.008) compared to the beginning and end of the course. Surprisingly self-reported stress, arousal and fatigue did not differ significantly across weeks, despite the large dropout rate (40%) and self-evident pressures of the course. We conclude that when controlling for many confounding variables, including participant adherence, post-awakening cortisol levels are sensitive to stressful challenge over a period of weeks.

Intraosseous infusion--a technique available for intravascular administration of drugs and fluids in the child with burns

Intraosseous infusion is a potential route for intravenous access in the child with burns who required vascular access that cannot be achieved in a timely manner via another route. Drugs, fluid and blood can be given via this route and marrow aspirate drawn for laboratory analysis. It is a reliable, safe procedure with a low incidence of complications.

Suggested sex and age appropriate values for "low" and "deficient" hemoglobin levels

New values for "deficient" and "low" Hb have been calculated as the smoothed 5th and the 15th percentiles for white males and females included in the National Health and Nutrition Examination Survey (NHANES I). With separate tabulations for 18.389 white individuals contained in this data base and for 12,320 with transferrin saturation values of 16% and above, these new values have the advantage of being fully age-specific, based upon a single source of hematological data and providing quantitative definitions of "low" and "deficient."

Severity of chest disease in cystic fibrosis patients in relation to their genotypes

A detailed comparison of the severity of chest disease with mutational status was carried out by cross sectional study of 127 cystic fibrosis patients, aged 1 to 31 years, living in Wales. Lung disease was classified according to severity, depending on pulmonary function tests (carried out on 76 patients) and chest radiograph status; information was obtained also on age at diagnosis in relation to severity of chest disease and colonisation with Pseudomonas species. Genotypes were determined by analysis for the mutations delta F508, delta I507, G551D, R553X, G542X, R117H, R560T, 1717--IG > A, and 621 + 1G > T. CF patients homozygous positive and heterozygous for the delta F508 deletion showed a significant decline of lung function with age. Unlike other studies, we did not find patients homozygous positive for the delta F508 deletion to have poorer lung function compared with heterozygous patients. Patients with the genotype 621 + IG > T/delta F508 tended to have more severe chest disease than the delta F508 homozygous patients in the same age group. There was some evidence that four patients heterozygous for R117H have mild chest disease.