Application of agonist-receptor modeling to the sweetness synergy between high fructose corn syrup and sucralose, and between high-potency sweeteners.

The agonist-receptor-transducer model of D. Ennis is applied to beverage formulations sweetened with high fructose corn syrup, sucralose, and other high-potency sweeteners, confirming the utility of the model, and supports the growing volume of evidence for multiple binding sites on the sweetness receptor. The model is further simplified to require less parameters for other sweetener blend systems whenever potency information is available for the single sweeteners.

The effects of shelf-life enhancers on E. coli K12 survival in needle-injected, surface contaminated beef strip steaks enhanced using recycled solutions.

The objective of this study was to evaluate the efficacy of shelf-life enhancers (sodium lactate [SL] or sodium lactate+sodium diacetate [SLDA]) on limiting the growth of Escherichia coli K12 in needle-injecting surface-contaminated beef strip steaks with recycled enhancement solutions. Strip loins were injected to 10% over initial weight. SLDA was most effective in controlling bacterial growth followed by SL alone. The salt/phosphate combination in the enhancement solution was ineffective. SL decreased a(∗) (less red) and b(∗) values (less yellow) of the steaks compared to the salt/phosphate control. SLDA decreased L(∗) values compared to SL alone. SL and SLDA were equally effective in reducing purge loss from the steaks. Steaks enhanced with a "fresh" enhancement solution had higher a(∗) values (more red) and higher E. coli contamination levels than steaks enhanced with recycled solutions. Recycling did not affect L(∗) value, b(∗) value, or purge loss.

The effects of shelf-life enhancers on E. coli K12 survival in needle-injected, surface contaminated beef strip steaks enhanced using recycled solutions.

The objective of this study was to evaluate the efficacy of shelf-life enhancers (sodium lactate [SL] or sodium lactate + sodium diacetate [SLDA]) on limiting the growth of Escherichia coli K12 in needle-injecting surface-contaminated beef strip steaks with recycled enhancement solutions. Strip loins were injected to 10% over initial weight. SLDA was most effective in controlling bacterial growth followed by SL alone. The salt/phosphate combination in the enhancement solution was ineffective. SL decreased a(∗) (less red) and b(∗) values (less yellow) of the steaks compared to the salt/phosphate control. SLDA decreased L(∗) values compared to SL alone. SL and SLDA were equally effective in reducing purge loss from the steaks. Steaks enhanced with a "fresh" enhancement solution had higher a(∗) values (more red) and higher E. coli contamination levels than steaks enhanced with recycled solutions. Recycling did not affect L(∗) value, b(∗) value, or purge loss.

Effect of carbon monoxide and high oxygen modified atmosphere packaging and phosphate enhanced, case-ready pork chops.

The objective of this study was to evaluate the effects of CO-MAP compared to traditional high oxygen MAP (HiOx-MAP) packaging and enhanced with different phosphate on enhanced pork quality. Pork loins were enhanced to 10.5% over initial weight to contain 0.3% salt and 0.4% phosphate (either sodium tripolyphosphate [STP] or a blend of STP and sodium hexametaphosphate) on a finished weight basis. Chops were cut, packaged in atmospheres containing 0.4% CO/30.0% CO(2)/69.6% N(2) (CO-MAP) or 80% O(2)/20% CO(2) (HiOx-MAP), aged in the dark, then placed in a lighted retail display case for 48h. Chops packaged in CO-MAP were redder (higher Minolta a(∗) values) and darker (lower Minolta b(∗) values) than chops packaged in HiOx-MAP. Based on sensory scores, the CO-MAP chops were pinker than the HiOx chops after cooking. CO-MAP chops also experienced less purge loss than chops in HiOx-MAP. Results indicate that CO-MAP had no effect on flavor or consumer acceptability and only minimal effects on other characteristics.

Analysis of risk factors associated with prostate cancer extension to the surgical margin and pelvic node metastasis at radical prostatectomy.

We analyzed data from 107 consecutive patients with clinical stage B prostate cancer in an attempt to identify those at high risk for having involved margins or nodal metastasis. Each patient underwent transrectal ultrasound-guided sextant biopsies of the prostate. Patient age, surgical approach to prostatectomy, pre-biopsy prostate specific antigen (PSA) level, and number, location and maximum Gleason score of positive biopsies were statistically evaluated for all patients groups. Prostate volume and PSA density (PSAD) were calculated for all patients undergoing prostatectomy. Of the 101 patients who underwent radical prostatectomy 64 had negative margins, 37 had at least 1 positive margin and 11 of the 37 had more than 1 positive margin. Involved margins were most common at the apex (62%) and mid portion (59%) of the gland. Prostatectomy was not performed on 6 patients with nodal metastases evident on frozen section examination. Therefore, 43 patients are considered to be at high risk for having residual disease after surgery. The mean PSAD, PSA level and number of positive biopsies were significant (p < 0.05) predictors of tumor extension to the surgical margin. The mean number of positive biopsies, biopsy Gleason score and PSA level were significantly greater (p < 0.05) in patients with nodal metastases. Only 15% of the patients with a single positive biopsy had positive margins versus 47% of those with multiple positive biopsies (p < 0.05). Of the patients with tumor positive nodes on frozen section 67% had 5 or more positive biopsies, whereas only 9% of all others had that many positive biopsies (p < 0.05). The number of positive biopsy sites, PSAD and PSA level were significantly associated with tumor at the surgical margin or metastatic to the pelvic nodes.

DNA as a solar dosimeter in the ocean.

Stratospheric ozone depletion may result in increased solar UV-B radiation to the ocean's upper layers and may cause deleterious effects on marine organisms. The primary UV-B damage induced in biological systems is to DNA. While physical measurements of solar UV-B penetration into the sea have been made, the effective depth and magnitude of actual DNA damage have not been determined. In the experiments reported here, UV-B-induced photoproducts (cyclobutane pyrimidine dimers) have been quantified in DNA molecules exposed to solar UV at the surface and at various depths in clear, tropical marine waters off Lee Stocking Island (23 degrees 45' N, 76 degrees 0.7' W), Exuma Cays, Bahamas. (14C)thymidine-labeled DNA or unlabeled bacteriophage phi X174 DNA was placed in specially designed quartz tubes at various depths for up to five days. Following exposure, DNA samples were removed to the laboratory where UV-B-induced pyrimidine dimers were quantified using a radiochromatographic assay, and bacteriophage DNA inactivation by solar UV-B was assayed by plaque formation in spheroplasts of Escherichia coli. Pyrimidine dimer induction was linear with time but the accumulation of dimers in DNA with time varied greatly with depth. Attenuation of dimer formation with depth of water was exponential. DNA at 3 m depth had only 17% of the pyrimidine dimers found at the surface. Bacteriophage phi X174 DNA, while reduced 96% in plaque-forming ability by a one day exposure to solar UV at the surface of the water, showed no effect on plaque formation after a similar exposure at 3 m. The data collected at the water's surface showed a "surface-enhanced dose" in that DNA damages at the real surface were greater than at the imaginary surface, which was obtained by extrapolating the data at depth to the surface. These results show the sensitivity of both the biochemical (dimers) and biological (phage plaques) DNA dosimeters. DNA dosimeters offer a sensitive, convenient and relatively inexpensive monitoring system, having both biochemical and biological endpoints for monitoring the biologically effective UV-B flux in the marine environment. Unlike physical dosimeters, DNA dosimeters do not have to be adjusted for biological effectiveness since they are sensitive only to DNA-mediated biologically effective UV-B radiation. Results of pyrimidine dimer induction in DNA by solar UV accurately predicted UV doses to the phage DNA.

Treatment of obliterated membranous and bulbous urethras by direct vision internal urethrotomy.

Acute placement of a suprapubic bladder tube followed months later by open urethroplasty has been the traditional manner for managing traumatic disruption of the proximal urethra. The latter procedure has generally been performed via the transpubic or perineal approach. These procedures have been complicated by excessive blood loss, impotence, incontinence, strictures, and extended hospitalizations. Since 1979, 12 patients with obliterated urethras (ten membranous, two bulbous) have been treated by direct vision urethrotomy using a second cystoscope or sound passed through the previously placed suprapubic tract as a guide. Mean blood loss, hospital stay, and followup were 70 ml, 6 days, and 22 months, respectively. Six patients required at least one additional internal urethrotomy. With the exception of one patient who still requires intermittent self-catheterization, all have stable strictures. Ten are continent (one was incontinent secondary to previous radical prostatectomy before urethrotomy and one became incontinent after a TURP performed 3 years after urethrotomy). Five are potent and none lost potency as a result of urethrotomy. Flow rates range from 15-25 ml/second in the continent patients. This is a reasonable first procedure for restoring continuity of traumatically obliterated membranous and bulbous urethras.

Emphysematous pyelonephritis complicated by hemorrhage, diagnosed by computerized tomography scan.

Emphysematous pyelonephritis complicated by a perirenal hematoma was diagnosed by computerized tomography. The computerized tomography scan was normal 3 months previously. Computerized tomography may be the procedure of choice to diagnose and stage emphysematous pyelonephritis.

Herpes simplex type 1 hepatitis in renal transplantation.

Herpes simplex is a rare but usually fatal cause of acute hepatitis in adults. Most previously reported cases have occurred in debilitated or immunosuppressed patients. We report two additional fatal cases that occurred in renal transplant recipients. In case 1, there is evidence that the allograft may have been the initial nidus of infection. In case 2, dissemination from a genital infection occurred and failed to respond to vidarabine therapy that was started early in the clinical course. We also review the literature concerning previously reported cases of herpes hepatitis.

Polypoid renal pelvic lesions in children.

A case is presented of gross hematuria and a large polypoid renal pelvic mass in a 15-month-old boy. Operation revealed a Wilms tumor with limited parenchymal involvement and rupture into the collecting system. This rare presentation of nephroblastoma and its differentiation from other rare benign and malignant renal pelvic lesions occurring in the pediatric patient are discussed. The advantages and disadvantages of radical and conservative surgical approaches to these rare lesions are reviewed. Preoperative cystoscopy and retrograde pyelography are mandatory in all patients with renal tumors presenting with gross hematuria, regardless of age. Radical nephrectomy with total ureterectomy is recommended for Wilms tumor with extension into the collecting system.

Vasovasostomy: evaluation of success.

Our review of 2,685 cases of vasovasostomy reported between 1948 and 1977 shows that many different surgical techniques can be successful. However, various reporting practices have made case comparisons difficult. We suggest a standardized method for reporting vasovasostomy results.