Letter to the Editor

No abstract available.

A candidate precursor to serous carcinoma that originates in the distal fallopian tube.

The tubal fimbria is a common site of origin for early (tubal intraepithelial carcinoma or TIC) serous carcinomas in women with familial BRCA1 or 2 mutations (BRCA+). Somatic p53 tumour suppressor gene mutations in these tumours suggest a pathogenesis involving DNA damage, p53 mutation, and progressive loss of cell cycle control. We recently identified foci of strong p53 immunostaining-termed 'p53 signatures'-in benign tubal mucosa from BRCA+ women. To examine the relationship between p53 signatures and TIC, we compared location (fimbria vs ampulla), cell type (ciliated vs secretory), evidence of DNA damage, and p53 mutation status between the two entities. p53 signatures were equally common in non-neoplastic tubes from BRCA+ women and controls, but more frequently present (53%) and multifocal (67%) in fallopian tubes also containing TIC. Like prior studies of TIC, p53 signatures predominated in the fimbriae (80-100%) and targeted secretory cells (HMFG2 + /p73-), with evidence of DNA damage by co-localization of gamma-H2AX. Laser-capture microdissected and polymerase chain reaction-amplified DNA revealed reproducible p53 mutations in eight of 14 fully-analysed p53 signatures and all of the 12 TICs; TICs and their associated ovarian carcinomas shared identical mutations. In one case, a contiguous p53 signature and TIC shared the same mutation. Morphological intermediates between the two, with p53 mutations and moderate proliferative activity, were also seen. This is the first report of an early and distinct alteration in non-neoplastic upper genital tract mucosa that fulfils many requirements for a precursor to pelvic serous cancer. The p53 signature and its malignant counterpart (TIC) underline the significance of the fimbria, both as a candidate site for serous carcinogenesis and as a target for future research on the early detection and prevention of this disease.

Influence of supplemental phytase on calcium and phosphorus utilization in laying hens.

A 6-wk study was conducted to determine the influence of supplemental phytase on Ca and P utilization in commercial laying hens. Diets were arranged factorially with three levels of dietary Ca (2.5, 2.8, and 3.1%), fed at two levels of nonphytate P (0.1 and 0.3% NPP) with and without supplemental phytase. Each diet was replicated eight times, with 16 hens per replicate. Criteria evaluated included egg specific gravity, feed consumption, egg production, egg weight, eggshell weight, bone quality, and body weight. Increasing dietary Ca significantly improved shell quality within 1 wk. A significant improvement in shell quality due to phytase supplementation was also observed during the 1st wk. Increasing NPP from 0.1 to 0.3% had not effect on egg specific gravity until Week 3, suggesting that the phytase benefit during Weeks 1 and 2 was related to improved Ca utilization. From Weeks 3 to 6, a significant P by phytase interaction was observed in which the magnitude of shell quality improvement was greatest when the 0.1% NPP diet was supplemented with phytase. This interaction was also observed from Weeks 3 to 6 for feed consumption and egg production and during Weeks 4 and 6 for egg weights. Phytase supplementation completely overcame the adverse effects associated with low dietary P and significantly reduced the impact of low dietary Ca on hen performance.

Performance of commercial laying hens fed various phosphorus levels, with and without supplemental phytase.

A 17-wk study was conducted to evaluate the effects of supplementing laying hen diets with a commercially produced microbial phytase. Hy-Line W-36 pullets (21 wk of age) were randomly allocated to 1 of 10 diets in a factorial arrangement of five levels of nonphytate phosphorus (0.1 to 0.5% NPP) and two levels of phytase (0 and 300 U/kg feed). Dietary metabolizable energy, protein, and calcium were maintained at 2,816 kcal/kg, 16.6%, and 4%, respectively. Criteria evaluated included egg production, feed consumption, egg weight, egg specific gravity, mortality, and various bone quality parameters. Feeding 0.1% NPP without supplemental phytase decreased egg production (hen-housed) 8.1% over the entire study and 29.6% over the last 4 wk, relative to other diets without supplemental phytase. Similarly, feed consumption of hens fed 0.1% NPP without phytase decreased 5.8% over 17 wk and 13.0% over the last 4 wk. Egg production and feed consumption were maintained at the level of other treatments without phytase when the 0.1% NPP diet was supplemented with phytase (82.1% and 82.4 g per hen per d, respectively). Egg weights and egg specific gravity decreased and mortality increased when hens consumed 0.1% NPP without phytase. Supplementing the 0.1% NPP diet with phytase completely corrected these adverse effects. No deficiency symptoms were observed in hens fed diets containing 0.2 to 0.5% NPP. Phytase supplementation of these diets gave no further improvements in performance.

The influence of environmental temperature on in vivo limestone solubilization, feed passage rate, and gastrointestinal pH in laying hens.

Several studies were conducted to determine whether suppression of in vivo limestone solubilization was partially responsible for the reduction of shell quality under conditions of high environmental temperatures. In Experiment 1, excreta from hyperthermic and thermoneutral hens fed three levels of Ca (3.5, 4.3, and 5.2%) at two cycling environmental temperatures (averaging 28.3 and 26.1 C) were analyzed for percentage in vivo limestone solubilization. Hens in Experiment 2 received diets containing 3.9% Ca at 32.8 and 18.3 C. Rate of feed passage and gastrointestinal pH were also measured in Experiment 2. Experiment 3 evaluated the influence of temperature (22.2 and 30.0 C) and feed consumption on percentage limestone solubilization when Ca intake was held constant. In vivo limestone solubilization was influenced by Ca level in Experiment 1, but not by temperature. Hyperthermic hens solubilized a higher percentage of limestone than thermoneutral hens in Experiment 2, but it was concluded that this was due to a difference in Ca consumption and not due to temperature directly. When Ca intake was held constant in Experiment 3, there was no difference in limestone solubilization at the temperatures tested. Rate of feed passage was 16.6% slower in the hyperthermic hens. Crop, proventriculus, and upper small intestine pH were similar at each temperature, but gizzard pH was significantly lower in the hyperthermic hens. It was concluded that the high environmental temperatures used in the present studies did not suppress in vivo limestone solubilization.

A method to determine and factors that influence in vivo solubilization of phosphates in commercial Leghorn hens.

Experiments 1 and 2 were conducted to establish a technique for the recovery of dietary phosphates from commercial layer manure. Solutions of ethanol, 60% ethanol:40% water (vol/vol), 50% ethanol:50% water, 40% ethanol:60% water, and 100% water were tested to determine the efficacy of dicalcium phosphate recovery. Solutions containing 50% or greater ethanol were found to be most effective. Experiments 3 and 4 were conducted to determine factors that influence in vivo phosphate solubilization in commercial Leghorn hens. In Experiment 3, mono-dicalcium phosphate (Biofos), di-monocalcium phosphate (Dynafos), and tricalcium phosphate (Multifos) were fed to layers at 1.67 and 3.3 g hen/d levels. In vivo phosphate solubilization was higher (P < or = .05) for Biofos and Dynafos than for Multifos. Dietary phosphate level did not consistently influence in vivo phosphate solubilization in hens. In Experiment 4, a 3 x 2 x 2 factorial arrangement consisting of three types of phosphates (Biofos, Dynafos, and Multifos), two dietary levels of added P (.3 and .6%), and two levels of dietary Ca (.88 and 3.75%) were used. In vivo phosphate solubilization decreased as Ca level was increased. In vivo solubilization of Multifos was lower than Biofos or Dynafos at both dietary Ca levels tested. These results indicate that phosphate source and calcium level, but not phosphorus level, consistently influence in vivo solubilization of phosphates.

A disposable end-tidal CO2 detector to verify endotracheal intubation.

STUDY OBJECTIVE: We compared the performance of the Fenem FEF end-tidal CO2 detector with the TRIMED capnometer to verify endotracheal intubation. DESIGN: The FEF indicates the presence of CO2 by the color change of a chemically treated indicator; the TRIMED uses infrared technology. Both devices were used during 60 intubations. SETTING: Intubations during in-hospital emergency situations outside of the operating room were studied. TYPE OF PARTICIPANTS: Adult patients undergoing intubation for respiratory failure, CPR, and other airway protection situations were enrolled in the study. INTERVENTIONS: The TRIMED monitor and FEF detector were placed in series between the manual resuscitator and the patient's endotracheal tube adapter after endotracheal tube placement. MEASUREMENTS AND MAIN RESULTS: We defined the acceptable criterion for detection of CO2 as production of a positive signal within six manual resuscitator bag breaths. The TRIMED met this criterion in 58 of 60 patients (sensitivity, 0.97) and the FEF met this criterion in 59 of 60 patients (sensitivity, 0.98). A paired t test showed no statistically significant difference in performance between the two devices. In five of nine cases of intubation during CPR, the color change of the FEF was described as "subtle." In one CPR case, a positive signal was not obtained by either device. CONCLUSION: We conclude that the performance of the FEF CO2 detector is equal to that of the TRIMED monitor for verification of endotracheal intubation in nonCPR situations. Interpretation of FEF color changes during CPR should be approached with caution until further studies using the FEF during CPR are completed.