Marination pressure and phosphate effects on broiler breast fillet yield, tenderness, and color

In the United States a large percentage of raw poultry meat is marinated prior to cooking. Many products are marinated by vacuum tumbling meat with a mixture of water, salt, and phosphates to increase cook yield and perceived tenderness. This study was designed to determine the effect of 3 pressure treatments (ambient, vacuum, or positive) and phosphate on yield, tenderness, and color on broiler breast meat. In each of 3 replicate trials, 60 broiler breast fillets were randomly assigned to a tumble marination treatment of 1) ambient tumble pressure (101 kPa); 2) vacuum tumble pressure (50 kPa); or 3) positive tumble pressure (204 kPa). Each pressure treatment was conducted with and without phosphate in the marination solution. Marination tumblers were operated at 15 rpm for 20 min at a temperature of 3 degrees C. Broiler breast fillets were weighed (raw, immediately after marination, 1 h postmarination, and after cooking), sheared after cooking with a Warner-Bratzler device, and evaluated for color (CIE L, a, and b) before marination and after cooking. Pressure and phosphate treatment combinations did not significantly (P < 0.05) affect marinated or drip weights, Warner-Bratzler shear values, cooked b, or percent drip loss. There was no effect of pressure treatment except for marinade uptake, where ambient tumble uptake was 12.7%, which was significantly higher than positive tumble (11.4%); vacuum tumble uptake (12.0%) was not different from either. Phosphate significantly increased cook weight (from 94.9 to 106.1 g) and cook yield (from 76.6 to 86.1%); L and a values were slightly but significantly decreased. Type of pressure during tumble marination had no effect except on marinade uptake, but the effect disappeared with 1 h holding time and cooking. Phosphate improved cook weight and yield. These data show that vacuum pressure during tumbling is not necessary, but phosphate is important to cook yields.

Moisture Retention by Water- and Air-Chilled Chicken Broilers During Processing and Cutup Operations

The objective of this study was to evaluate effects of storage and cutting on moisture retention by air- and water-chilled broiler chickens. Sixty-four broilers were slaughtered, chilled by cold air or immersion in water, stored over night, cut into fore- and hindquarters, and then stored an additional 24 h. Air chilling conditions were 4 degrees C with air velocity of 2.2 m3/min. Water chilling conditions were 1 degree C with mechanical agitation. Moisture absorption and retention were observed as weight changes throughout the process. Air-chilled carcasses lost an average of 0.68% of their postslaughter weight in storage prior to cutting but lost no more during cutting or postcutting storage. The water-chilled carcasses absorbed 11.7% moisture in chilling but retained 6.98% through precutting storage, 6.00% through cutting and 3.90% through postcutting storage. These data offer baseline values for use in complying with new USDA processing standards.

Effect of Vacuum on Moisture Absorption and Retention by Marinated Broiler Fillets

Effects of vacuum on moisture retention and quality characteristics of aged chicken breast fillets were evaluated. One hundred twenty-eight broilers (2 replicates of 64 birds each) were manually slaughtered, chilled in ice water, placed in unsealed plastic bags, and then aged overnight at 4 degrees C. Both pectoralis major muscles were harvested from each carcass. Left muscles were marinated for 30 min en vacuo with 20% (vol/wt) of a 10% NaCl (wt/vol) solution containing 4% (wt/vol) commercial food-grade polyphosphate. Right fillets were marinated similarly but without vacuum. Moisture absorption, cooked yield, pH change during marination, and shear values of vacuum-marinated fillets were compared to those on fillets marinated without vacuum. Use of vacuum during marination increased moisture absorption during marination, but after cooking, yields were similar. Nor did vacuum effect pH or shear values. Under the conditions of this study, use of vacuum during marination appeared to offer no significant advantage over marination at atmospheric pressure.

Influence of age and postchill carcass aging duration on chicken breast fillet quality

Breast fillet quality was evaluated from 37-, 39-, 42-, 44-, 46-, 49-, and 51-d-old broilers after post-chill (PC) aging of the carcass 0, 2, 4, or 6 h and deboning. Fillets were vacuum sealed in cooking bags and heated to an internal temperature of 72 C by submersion in a 95 C water bath. Cook yield was determined as the weight percentage of the fillet remaining after cooking. Texture of the cooked fillets was measured using a Warner-Bratzler (W-B) shear device. Fillet cook yield and shear force values were significantly affected by bird age at slaughter, and PC carcass aging duration before deboning. Bird gender significantly affected cook yield, whereas the interaction between age and PC aging duration significantly affected W-B shear. Fluid lost during cooking was greater for fillets aged 0 h PC and decreased when PC aging was 2 h or greater. Overall, W-B shear values decreased (more tender) when fillets were aged on the carcass at least 2 h PC, with the exception of fillets from 51-d-old broilers. After 2 h of PC aging on the carcass, shear force values for fillets from older broilers (49- and 51-d-old) were in the "very tough" portion of a texture scale (>12.60 kg), whereas textures of fillets from 42- and 44-d-old broilers were in the "slightly tough to slightly tender" portion of the scale (8.5 and 7.2 kg, respectively). These data show that if poultry processors harvest fillets earlier than usual (<2 h PC aging), the fillet texture will be more tender if it originates from younger broilers (42- or 44-d-old) instead of older broilers (49- or 51-d-old).

Effects of age, sex, and duration of postmortem aging on percentage yield of parts from broiler chicken carcasses

The objective of this study was to evaluate effects of age, sex, and postmortem carcass aging duration on parts yield from broiler chickens. Two hundred twenty-four mixed-sex broilers were reared under commercial-like conditions for various periods between 37 and 51 d, slaughtered, packed in ice, and then aged for 0, 2, 4, or 6 h. Mean percentage yield of thighs, drumsticks, forequarters, wings, breasts, and filets were evaluated for each rearing period, sex, and postmortem aging duration. Yield of meatier parts such as thighs, forequarters, breasts, and filets increased with birds' ages. Female carcasses produced higher percentage yields of forequarters, breasts, and filets but lower yields of drumsticks. Carcasses aged 2 h or more postmortem tended to have lower yields of forequarters, breasts, and drumsticks than did carcasses aged for shorter durations. No statistically significant interactions among age, sex, or postmortem aging duration that affected yield of parts were detected. This information is useful to integrated poultry firms wishing to optimize yield of the most commercially valuable parts.

Effect of electrical stimulation and polyphosphate marination on drip from early-harvested, individually quick-frozen chicken breast fillets

Individual and combined effects of electrical stimulation and polyphosphate marination on drip and other quality attributes of early-harvested, individually quick-frozen chicken breast fillets were evaluated. Broiler chickens were slaughtered, half conventionally processed and half with electrical stimulation. Fillets were harvested 1 h postmortem and marinated in either NaCl solution or NaCl plus polyphosphate solution. Marinade absorption, pH, drip, cooking loss, and shear values were observed. Electrical stimulation had no direct effect on pH, cooking loss, or shear values, whereas polyphosphate increased pH and decreased cooking loss. Polyphosphate treatment caused fillets from unstimulated carcasses to absorb more marinade and yielded more drip that those from stimulated carcasses. Fillets from stimulated carcasses marinated in NaCl solution without polyphosphate yielded less drip than those from unstimulated carcasses. Polyphosphate reduced drip of fillets from unstimulated carcasses but not of those from stimulated carcasses. Results support previous reports indicating interactions between polyphosphates and processing parameters that can affect ultimate quality of poultry meat products.

LEA.135 expression: its comparison with other prognostic biomarkers for patients with primary breast carcinoma

The purpose of this retrospective study was to examine the prognostic value of expression of luminal epithelial antigen (LEA.135) for recurrence and overall survival of patients with primary invasive breast carcinoma by both univariate and multivariate analyses. The possible prognostic value of LEA.135 was also compared with some widely utilized prognostic biomarkers such as c-erbB 2, topoisomerase II.alpha (TPII.alpha), MIB 1, estrogen receptor (ER) and progesterone receptor (PR), as well as age of the patients and clinicopathologic parameters. The study was carried out by immunohistochemical methods on formalin-fixed/paraffin-embedded tissue sections in a series of 225 patients with median follow-up of 8.5 years. Prognostic significance of the biomarkers was determined by two-sided p value. In this series of patients, among the age and clinicopathologic parameters, only age, was significantly associated with a decreased overall survival (logrank p = 0.027). Among the prognostic biomarkers, TPII a expression at high (> 50% positive cells) or moderate (6-50% positive cells) level was associated with an increased rate of recurrence (logrank p < 0.001). However, the association of TPII.alpha expression with a decreased overall survival failed to reach a statistically significance. Expression of c-erbB 2 showed a trend of being associated with an increased probability of recurrence, but the association did not reach statistical significance. The remaining biomarkers were not associated with either the probability of recurrence or overall survival. LEA.135 expression was observed in 163 (72.4%) of the 225 patients. The patients with high (> 50% positive cells) or moderate (6-50% positive cells) level of LEA.135-positive cancer cells showed a significantly decreased probability of recurrence (logrank p < 0.001) and an increased overall survival (logrank p < 0.001) compared with those with LEA.135-negative cancer cells. The association remained significant by multivariate analysis for recurrence (likelihood ratio test p < 0.001) and overall survival (likelihood ratio test p < 0.001) when assessed with other prognostic parameters. Furthermore, the combination of LEA.135 with other prognostic biomarkers stratified four subgroups of patients with distinct clinical outcome. The subgroup of patients who were LEA.135+/TPII.alpha- showed the lowest probability of recurrence and the longest overall survival compared with those who were LEA.135-/TPII.alpha+ (logrank p < 0.001). Interestingly, the patients whose cancer cells were LEA.135+/TPII.alpha+, LEA.135+ MIB.1+ or LEA.135+/c-erbB 2+ experienced a decreased probability of recurrence and an increased overall survival compared with those with LEA.135-/TPII.alpha+, LEA.135- MIB.1+ or LEA.135-/c-erbB 2+ (logrank p < 0.001). The results demonstrated that LEA.135 is an independent and favorable prognostic biomarker for patients with primary invasive breast carcinoma, that the loss of LEA.135 expression is associated with aggressive phenotype of cancer cells during the breast cancer progression, and that its continued expression seems to override the adverse effects of expression of an oncogene or cell proliferation-associated molecules.

Calcium-induced modification of protein conformation demonstrated by immunohistochemistry: What is the signal?

A recent study by Morgan et al. on the mechanism of the heating antigen retrieval (AR) has raised an interesting issue concerning calcium-induced modification of protein conformation demonstrated by immunohistochemistry (IHC). The current study is based on calcium-induced modification of thrombospondin (TSP) and Ki-67, as demonstrated by IHC using seven monoclonal antibodies (MAbs) to TSP and an MAb MIB1. Experiments were carried out on frozen tissue sections of bladder carcinoma and lymph node. Frozen sections were incubated with solutions of 50 mM CaCl2 and/or 10 mM EDTA at 4C overnight before formalin or acetone fixation for TSP and Ki-67, respectively. Sections were then fixed in 10% neutral buffered formalin or acetone before immunostaining. Seven MAbs to TSP, named Ab1 to 7 representing clone numbers of A4.1, D4.6, C6.7, A6.1, B5.2, A2.5, and HB8432, respectively, and MIB1 were utilized as primary antibodies. ABC was used as the detection system and AEC as the chromogen for immunohistochemical staining. An extracellular immunostaining pattern represented a positive result for TSP, and nuclear staining for MIB1. Frozen sections preincubated in 50 mM CaCl2 overnight at 4C showed significant loss of staining and/or altered staining pattern for six of the seven antibodies to TSP and MIB1 compared to positive controls not exposed to CaCl2. Lack of immunostaining of TSP and MIB1 attributable to exposure to CaCl2 could be partially recovered by incubating the frozen sections in EDTA. Calcium-induced modification of protein structure was demonstrated more than 10 years ago on the basis of immunochemical techniques. In this study, similar calcium-induced modification of protein was detectable by IHC in frozen tissue sections, suggesting that calcium-induced modification of protein structure may occur independently of fixation-induced modification. The fact that calcium binding may affect IHC staining is not surprising in view of the fact that antibody/antigen interactions are protein structure-dependent. However, in this experiment the change occurred before and independent of formalin fixation and does not necessarily imply a role for calcium in AR. There may be a valuable role for the use of chemical modification in visualization of protein structure changes in tissue sections by IHC. (J Histochem Cytochem 47:463-469, 1999)

Immunohistochemical identification of androgen receptors in human lacrimal glands

PURPOSE

Androgens are thought to play a role in the regulation of the human lacrimal gland. Androgen receptor mRNA has been isolated from human lacrimal tissue; however, it is not known which cell(s) in human lacrimal tissue may contain androgen receptors. This study is an immunohistochemical investigation of the location and distribution of androgen receptors in human lacrimal tissue.

METHODS

Formalin-fixed, paraffin-embedded human lacrimal gland tissues were subjected to established antigen retrieval techniques. This was followed by routine immunohistochemical staining, employing one of two anti-human androgen receptor monoclonal antibodies, each specific for a different antigenic epitope within the receptor molecule.

RESULTS

The two anti-human androgen receptor monoclonal antibodies demonstrated similar staining patterns in adjacent tissue sections from the same human lacrimal gland specimens. Specific staining for androgen receptors was observed in the nucleus and cytoplasm of lacrimal acinar cells, as well as in lacrimal duct cells. Both the intensity of staining and the number of cells demonstrating staining varied among specimens. We also observed staining for androgen receptors in interstitial and inflammatory cells distributed between lacrimal acinar units in some specimens.

CONCLUSIONS

Androgen receptors are located in human lacrimal gland acinar cell nuclei as observed in other animals. However, the detection of androgen receptors in lacrimal interacinar interstitial and inflammatory cells suggests that androgens may play a role in modulating the activities of cells other than lacrimal cells within the human lacrimal gland.

Effect of polyphosphate treatment and electrical stimulation on postchill changes in quality of broiler breast meat

The objective of this study was to assess effects of treating electrically stimulated broiler forequarters with polyphosphates after various aging periods on quality. Ninety-six mixed sex broilers were electrically stunned and slaughtered. Half the carcasses were electrically stimulated during bleeding and half were not. Forequarters were harvested immediately after chilling and after 2, 4, and 6 h postchill. Left forequarters were marinated in salt solution and right forequarters in salt solution plus sodium tripolyphosphate. After marination, the quarters were cooked. Yield and meat pH were evaluated immediately after marinating; and color, yield, and cooking loss were evaluated after cooking. Electrical stimulation resulted in a decline in muscle pH for the 0 postchill group. The pH of muscles from unstimulated and stimulated carcasses from the remainder of the postchill times were equivalent. Phosphate treatment increased pH at all postchill times. Electrical stimulation of the marinated quarters increased cooking loss and decreased yield regardless of marinade composition. Both cooking loss and yield were superior for forequarters harvested at 0 or 2 h postchill compared to those harvested at 4 or 6 h postchill. The phosphate improved moisture binding regardless of electrical treatment or time of harvest. Color values of cooked muscles were unaffected by marination time, but the phosphate-treated muscles had higher b* (yellowness) values than controls. Shear values of unstimulated carcasses that received phosphate treatment were 35% greater than those that received no phosphate treatment. When the carcasses were electrically stimulated, the toughening effect of the phosphate was eliminated.

Influence of preslaughter stunning on turkey breast muscle quality

Pectoralis muscle quality was evaluated from 18-wk-old tom turkeys after electrical stun, carbon dioxide stun, or no stun methods were applied. Color was measured on raw muscle and cooked meat using a colorimeter. Muscle pH was measured 15 min post-mortem (initial), 24 h post-mortem (final), and after cooking. The right Pectoralis muscle of each carcass was excised for m-calpain analysis within 4 min post-mortem. After 24 h of storage at 4 C, the left Pectoralis muscle was excised to determine cook loss and shear force measurements. No significant difference was found in initial muscle pH (15 min) from turkeys receiving electrical or carbon dioxide stunning, 6.36+/-0.15 and 6.20+/-0.14, respectively. However, initial muscle pH for birds that were not stunned (5.99+/-0.08) was lower (P < 0.05) than the muscle pH of birds stunned using either of the two stunning methods. Stunning method had no effect on the final muscle pH, raw muscle color, cooked meat pH, cooked meat color, cook loss, or shear force. Cook loss was found to positively correlate with initial muscle lightness (r = 0.53), and cooked meat lightness (r = 0.48), but to negatively correlate with cooked meat yellowness (r = -0.48) and shear strength (r = -0.43). m-Calpain activity declined with the stunning methods in the following order: electrical > carbon dioxide > no stun. In addition, m-calpain activity was found to correlate with initial muscle pH (r = 0.95) and with cooked meat shear force (r = -0.43). The results of this study show that electrical stunning, carbon dioxide stunning, and no stunning methods provide comparable cooked turkey breast meat quality with no consistent differences after aging on the carcass for 24 h.

Effects of age and tissue type on the calpain proteolytic system in turkey skeletal muscle

A study was conducted to examine the effects of bird age and muscle tissue type on calpain and calpastatin activities in turkey skeletal muscle. Enzymatic activities of calpains and calpastatin were found to vary with bird age and muscle type. Breast muscle from younger birds (age 5 wk) had higher mu-calpain, m-calpain, and calpastatin activities (P < 0.05) than breast muscle from older birds (9, 13, and 17 wk of age). Thigh muscle calpain activities were not affected by bird age, but thigh calpastatin activity was found to increase with age, with muscle from 17-wk-old birds having 35% higher activity than muscle from 13-wk-old birds. When extracted from 9-wk-old turkeys, breast muscle mu-calpain activity was 30% higher than thigh muscle mu-calpain. By 13 wk of age, breast muscle mu-calpain activity was 20% less than thigh mu-calpain. Thigh muscle m-calpain and calpastatin activities were found to be significantly higher (P < 0.05) than that found in breast muscle, with some values more than double in older birds (17 wk of age).

Effect of postchill aging and sodium tripolyphosphate on moisture binding properties, color, and Warner-Bratzler shear values of chicken breast meat

The objective of this study was to assess the effects of treating chicken breast forequarters with sodium tripolyphosphate (STPP) after various postchill storage times on meat quality. Sixty-four commercially reared broilers (two replicates of 32 birds each) were slaughtered and chilled, and then the forequarters (split breasts with spine and ribs) were harvested and aged for 0, 120, 180, or 240 min postchill. After each aging period, one forequarter from each of 16 birds was marinated with a NaCl solution and the opposite forequarter was marinated with the same NaCl solution containing STPP. The quarters were then cooked and the following traits measured: marinade absorption, cooking loss, objective color values, and Warner-Bratzler shear values. As aging time prior to marination increased, cooking loss and redness of the cooked meat decreased, but marinade absorption and the color values were unaffected. The STPP treatment increased marinade absorption, decreased cooking losses, and decreased cooked meat redness (P < 0.05). Shear values decreased with aging time for both the control and STPP-treated breast meat. When the STPP treatment was applied immediately after carcass chilling, the STPP-treated meat exhibited shear values more than 60% greater than those of the controls (9.14 and 5.69 kg, respectively). Results indicate that time postchill at which further processed products are treated with STPP can have a significant effect on quality, especially cooked product texture.

Effect of electrical stimulation in combination with calcium chloride or sodium chloride treatments at constant ionic strength on moisture binding and textural quality of early-harvested breast fillets

The objective of this study was to assess the effects of a CaCl2 or NaCl treatment combined with electrical stimulation (ES) on textural and moisture binding of early-harvested chicken breast fillets. During exsanguination, half the birds were subjected to ES, and then all carcasses were aged for 30, 60, 90, or 120 min before excising both Pectoralis major muscles. Half the muscles were chilled with a NaCl solution and half with a CaCl2 solution. Effects of ES and chill medium composition on meat pH, moisture absorption, cooking loss, and shear value of the fillets were assessed. The ES reduced meat pH for the NaCl-treated muscles, but had no effect on those treated with CaCl2 of on moisture absorbed during chilling. Cooking loss was greater for the CaCl2-treated than NaCl-treated muscles and for muscles from stimulated birds that were excised more than 30 min post-mortem. Shear values were unaffected by chilling medium composition. However, even though shear values for both ES and unstimulated birds declined as aging time increased, the rate of decline was greater, and ultimate shear value lower, for muscles from ES birds. Results indicate that, although ES might offer some advantage in improving the tenderness of early-harvested breast fillets, combining ES with CaCl2 treatment offers no real advantage. Moreover, reductions in moisture binding properties by these technologies might limit applicability in some commercial environments.

Effects of stunning duration on quality characteristics of early deboned chicken fillets

The objective of this study was to determine effects of electrical stunning duration on quality of broiler chicken fillets. Seventy-two broiler chickens were electrically stunned for 0, 2, 4, 6, 8, or 10 s, slaughtered, and chilled. After 1 h post-mortem, both pectoral muscles were excised and cooked. Cooking loss, pH, cooked color values, and shear values were measured. As stunning time increased, pH and shear values significantly increased. Except for a small but significant increase in yellowness, color values were unaffected by stunning duration. Cooking loss was unaffected by stunning duration. These data indicate that stunning duration can affect post-mortem muscle metabolism as measured by pH change. Therefore, control of the process of slaughtering broilers requires careful regulation of stunning duration.

Informed consent and parental choice of anesthesia and sedation for the repair of small lacerations in children

This study investigated the issue of informed consent by surveying parent preferences for local anesthesia and sedation in the repair of small lacerations in their children in the emergency department (ED). Of the 45 ED patients with actual lacerations receiving a suture repair, 11 requested tetracaine-adrenaline-cocaine (TAC), 25 requested infiltrated lidocaine, and 9 were not given a choice (lidocaine administered because of wound proximity to a mucous membrane site). All 45 patients preferred nonsedation over sedation. In 44 of 45 patient cases, parents preferred to be included in the medical decision-making for their children. Of the 94 non-ED cases (interviewed in private offices) with a hypothetical chin laceration, 16 preferred TAC and 78 preferred infiltrated lidocaine. Sixty-seven of 94 preferred nonsedation over sedation. In 89 of 94 patient cases, parents preferred to be included in the medical decision-making for their children. Favorable points of continuous informed consent were presented, with risks, benefits, and alternatives disclosed. From the data presented, the following conclusions were drawn: (1) parents preferred infiltrated local anesthesia more commonly than topical local anesthesia; (2) parents preferred nonsedation over sedation under the clinical circumstances described; (3) parents overwhelmingly preferred to be included in the medical decisions affecting their children.

Stool appearance in intussusception: assessing the value of the term "currant jelly"

This study surveyed the stool appearance descriptions of 107 inpatient children with intussusception. Fifty-six patients presented with grossly bloody stools (passed spontaneously), 10 of which were determined on chart review to resemble currant jelly. Of the 51 patients without grossly bloody spontaneously passed stools, 35 patients had rectal examination results charted. Eight of these children had grossly bloody stools noted on rectal examination, 4 of which were determined on chart review to resemble currant jelly. While most of the grossly bloody stools were not consistent with pure currant jelly, the most common terms used in describing the grossly bloody stools were "bloody," "mucus," "red," and "diarrhea." Since stools truly resembling currant jelly account for a minority of the grossly bloody stools in intussusception, the term "currant jelly stools" should be assessed in the teaching of intussusception. Generic terms such as blood, mucus, burgundy, red, etc, are more objective and sensitive at identifying cases of intussusception. Junior physicians who are taught the classic presentation of intussusception with currant jelly stool should also be taught that intussusception should be considered in the differential diagnosis of children passing any type of bloody stool. As a result, physicians with limited experience will be more likely to appropriately consider the diagnosis of intussusception, permitting a more timely diagnosis and a better outcome.

Identification of the rat maternally transmitted minor histocompatibility antigen

The rat maternally transmitted Ag has been previously described as a minor histocompatibility Ag composed of a mitochondrially transmitted factor (MTF) and the RT1.Aa MHC class I molecule. We compared the DNA sequences of the 13 mitochondrial open reading frames from different rat strains and identified four coding polymorphisms that correlated with this MTF. We used synthetic 17-mer peptides spanning the polymorphisms to sensitize appropriate target cells in lymphocytotoxicity assays and found that the MTF is derived from an internal region of ATPase 6. A tridecameric derivative of the ATPase 6 17 mer (termed 13N3E) could sensitize RT1.Aa-expressing target cells at picomolar concentrations and, when present on such cells, could compete fully with the natural ligand in cold-target competition assays. Comparing the 13N3E peptide with the known peptide-binding requirements of RT1.Aa suggested two possible binding conformations, placing either an internal or a C-terminal arginine in the F pocket of the peptide-binding groove. Arguments favoring a "bulging" conformation, with N- and C-terminal residues bound into their conserved pockets, are discussed.

Identification of the rat maternally transmitted minor histocompatibility antigen

The rat maternally transmitted Ag has been previously described as a minor histocompatibility Ag composed of a mitochondrially transmitted factor (MTF) and the RT1.Aa MHC class I molecule. We compared the DNA sequences of the 13 mitochondrial open reading frames from different rat strains and identified four coding polymorphisms that correlated with this MTF. We used synthetic 17-mer peptides spanning the polymorphisms to sensitize appropriate target cells in lymphocytotoxicity assays and found that the MTF is derived from an internal region of ATPase 6. A tridecameric derivative of the ATPase 6 17 mer (termed 13N3E) could sensitize RT1.Aa-expressing target cells at picomolar concentrations and, when present on such cells, could compete fully with the natural ligand in cold-target competition assays. Comparing the 13N3E peptide with the known peptide-binding requirements of RT1.Aa suggested two possible binding conformations, placing either an internal or a C-terminal arginine in the F pocket of the peptide-binding groove. Arguments favoring a "bulging" conformation, with N- and C-terminal residues bound into their conserved pockets, are discussed.

Effect of calcium marination on biochemical and textural properties of peri-rigor chicken breast meat

The objective of this study was to evaluate effects of marinades containing varying calcium concentrations on the biochemical and texture characteristics of peri-rigor chicken breast fillets. Breast muscles from 200 broiler chickens were excised immediately post-mortem and marinated in 0, 50, 100, 150, or 200 mM CaCl2. The treatments had no effect on meat pH either before or after cooking, but as calcium concentration increased, the normal post-mortem conversion of adenosine triphosphate (ATP) to inosine monophosphate (IMP) increased, according to the IMP:ATP ratios (R-values). Calcium treatment at all levels tested improved meat tenderness, but both marinade absorption and cooking losses increased as the calcium concentration in the marinades increased. It was concluded that although treating peri-rigor breast muscle with calcium might be useful in reducing or eliminating the conditioning period to assure tender chicken, methods must be developed for restoring the moisture binding properties that are damaged by the calcium.

Effect of stunning time and polyphosphates on quality of cooked chicken breast meat

The objective of this research was to determine effects of stunning duration and polyphosphates on color, pH, and texture of chicken breast meat. Sixty broiler chickens were electrically stunned for 2 to 10 s in 2-s intervals and then slaughtered. Left and right Pectoralis major muscles were excised 1 h post-mortem. The left muscles (treated) were treated with a sodium tripolyphosphate salt solution, and the right muscles (controls) were treated with a salt solution alone. All muscles were cooked to an endpoint temperature of 72 C in a 95 C water bath. Measurements of muscle pH were taken on the meat 1 h post-mortem, after treating, and after cooking. Color values and Warner-Bratzler shear values were evaluated on each cooked meat sample. As stunning time increased, pH increased at 1 h post-mortem but treating with either of the solutions eliminated this trend. Muscle pH also increased upon cooking except in the polyphosphate-treated muscles, because the latter muscles achieved maximum pH prior to cooking. Stunning had no apparent effect on color values of the cooked meat; however, polyphosphate treatment resulted in meat that was darker and less red than controls. Longer stunning times resulted in greater shear values but polyphosphates did not affect Warner-Bratzler results. Taken together, these data suggest that processing variables that affect muscle pH also affect quality attributes.

The rat cim effect: TAP allele-dependent changes in a class I MHC anchor motif and evidence against C-terminal trimming of peptides in the ER

Functional polymorphism in the rat peptide transporter associated with antigen processing (TAP) changes the peptide pool available for binding and presentation by a class I MHC allele, RT1.Aa. The peptide binding motif for RT1.Aa, determined by stabilization with synthetic peptides, included a strong preference for arginine at the peptide C terminus. Analysis of natural peptides bound to RT1.Aa by both pool sequencing and anhydrotrypsin chromatography revealed that TAP polymorphism determined the presence or absence of arginine as the peptide C-terminal residue. This result highlights the in vivo impact of TAP-peptide selectivity, and provides evidence against a high rate of generation of new C termini by protease activity in the endoplasmic reticulum.

Incidence of occult lymph node metastases in pathological stage C (pT3N0) prostate cancer

PURPOSE

To determine the incidence of occult lymph node metastases in patients with stage pT3N0 prostate cancer.

MATERIALS AND METHODS

Lymph nodes from 95 patients with stage pT3N0 prostate cancer were analyzed by immunohistochemistry for extrinsic epithelial cells using epithelial-specific monoclonal antibodies. The extrinsic epithelial cells were also tested for prostate specific antigen expression.

RESULTS

Occult lymph node metastases were identified in 15 cases (16%) and were more frequent in patients with high primary Gleason grade tumors and seminal vesicle invasion (p = 0.03). In all cases the extrinsic cells were of prostate origin based on prostate specific antigen expression.

CONCLUSIONS

Occult lymph node metastases can be detected in a substantial proportion of patients with stage pT3N0 prostate cancer, are associated with known predictors of disease progression, and may be useful in identifying patients at risk for recurrence and progression.

Generation of a murine monoclonal antibody to normal mammary epithelium using mice rendered immune-tolerant to malignant mammary epithelium

A monoclonal antibody (MAb) that distinguishes normal from malignant mammary epithelia in tissue or cell lines was generated using a procedure that involved immune-tolerization before immunization. Immune-tolerance to two transformed mammary epithelial cell lines (MCF.7 and MDA.MB.231 cell lines combined) was induced in neonatal mice within 24 hr of birth. Successful induction of immune-tolerance was determined by an indirect immunohistological method, testing sera from mice against the tolerogen (i.e., the MCF.7 and MDA.MB.231 cell lines). Mice lacking antibodies in their sera against the immune-tolerogen were subsequently immunized with an extract of normal breast epithelium. One mouse was selected for hybridoma production based on evidence of serum antibody that showed reactivity with normal mammary epithelial cells (MEC) but not with invasive breast carcinoma cells, as determined by an indirect immunohistological method. Spleen cells from the selected mouse were fused with a mouse myeloma cell line to generate MAb. After extensive screening, one MAb was further studied on the basis of reactivity with normal MEC in tissue and absence of staining of malignant MEC in tissue or tumorigenic MEC lines. This test of specificity of reactivity revealed that the antigen detected by the specific antibody was expressed on the apical plasma membrane of normal glandular epithelia that included breast, cervix, colon, lung, pancreas, and stomach, but not on their malignant counterparts in tissue sections. The antigen recognized by the MAb was termed luminal epithelial antigen with an apparent MW of 92 KD (LEA.92). This study illustrates the practical usefulness of the immune-tolerization/immunization approach in the generation of antibodies with particular specificity requirements, as in the identification of an antigen that is differentially expressed in two tissues (e.g., normal and malignant) which otherwise have a multiplicity of antigens in common.

Effect of pH and ionic strength on bovine m-calpain and calpastatin activity

The effects of bovine skeletal muscle m-calpain and calpastatin on the degradation of casein and isolated bovine myofibrils were characterized under various pH values (7.0, 6.2, 5.7) and ionic strengths (32 to 400 mM KCl) at 25 degrees C. Caseinolytic assays indicated that m-calpain activity increased with increasing pH (P < .01) but decreased with increasing ionic strength (P < .01). Regardless of the presence of m-calpain, SDS-PAGE of myofibrils showed increased solubilization of myofibrillar proteins as pH and ionic strength increased. However, only in the presence of m-calpain were changes normally observed during postmortem storage reproduced. Protein release attributed to m-calpain activity increased with pH, but the effects of elevated ionic strength on the ability of m-calpain to hydrolyze myofibrillar proteins were not evident from SDS-PAGE, except for the decreased troponin-T degradation by m-calpain at the higher ionic strengths. A pH x ionic strength interaction was observed for calpastatin activity determined by caseinolytic assays (P < .01). No changes in m-calpain inhibition were detected at pH 7.0 and 6.2 at different ionic strengths. However, at pH 5.7 the ability of calpastatin to inhibit m-calpain decreased with increasing ionic strength. No changes in m-calpain inhibition could be detected with SDS-PAGE. Based on these results, it can be concluded that although m-calpain and calpastatin activities decrease with increasing ionic strength, their activities in the presence of myofibrils were not affected by ionic strengths typically found in postmortem muscle.

The judicial use of venous duplex imaging and strain gauge plethysmography (single or combined) in the diagnosis of acute and chronic deep vein thrombosis

Sixty-eight patients (79 limbs) with clinically suspected deep vein thrombosis were evaluated by duplex imaging, strain gauge plethysmography and venography. The diagnostic accuracies were projected over a spectrum of disease incidences ranging from 10 to 90 per cent of the population. The sensitivity, specificity, positive and negative predictive values, and over-all accuracy in detecting acute deep vein thrombosis were 90.9, 87.1, 83.3, 93.1, and 88.7 per cent, respectively, for venous duplex imaging, and 81.8, 69.6, 56.3, 88.9 and 73.5 per cent, respectively, for strain gauge plethysmography. The positive predictive value and over-all accuracy of venous duplex imaging were statistically significantly higher than that of strain gauge plethysmography. When both tests were combined and compared with venous duplex imaging alone, none of these parameters were statistically significant. For chronic deep vein thrombosis, the sensitivity, specificity, positive predictive value, negative predictive value and over-all accuracy for venous duplex imaging were 75, 86, 80, 86 and 82 per cent, respectively. Fourteen per cent had inconclusive results obtained at venous duplex imaging. When strain gauge plethysmography was combined with venous duplex imaging, the over-all accuracy was 82 per cent. As the true incidence of the disease increases, the positive accuracy differences between strain gauge plethysmography and venous duplex imaging decrease to a negligible level. We concluded that over-all, venous duplex imaging is superior. However, the strain gauge plethysmography has reasonable accuracy and may be used in places where venous duplex imaging is not available. Combined use of venous duplex imaging and strain gauge plethysmography would be helpful in patients with inconclusive results obtained at venous duplex imaging and, as the true incidence increases, the positive accuracy rate of strain gauge plethysmography becomes close to that of venous duplex imaging.

Episodic factitious gingival injury secondary to topical anesthesia. A case report

The contribution of topical anesthesia to the incidence of severe factitious gingival injury in an adult patient is reported. A brief review of the literature is also presented.

Comparison of microscopic and laser diffraction methods for measuring sarcomere lengths of contracted muscle fibers of chicken pectoralis major muscle

The objective of the present study was to compare the effectiveness of a microscopy method with a laser diffraction method for measuring sarcomere lengths of chicken pectoralis major (p. major) muscle fibers exhibiting various contraction states. Chicken p. major muscles were excised from the animals at death. Samples of each muscle were treated with pH-buffered (5.0 and 7.5) isoionic CaCl2, KCl, or ethylene glycol bis-(b-aminoethyl ether) N,N,N',N'-tetraacetic acid (EGTA) solutions in order to produce variability in the degree of fiber contraction. Sarcomere lengths (SL) of the fibers were observed using light microscopy and a laser diffraction method. The methods gave comparable results for sarcomere lengths greater than 1.6 microns. However, for SL less than 1.6 microns, sarcomere contraction was not accurately assessed by the laser diffraction method.

Rapid headspace gas chromatographic method for assessment of oxidative stability of cooked chicken meat

Experiments were conducted to determine the volatile compounds in cooked chicken meat using a static headspace gas chromatographic (GC) technique. Preheating conditions for samples in vials were tested at 70, 80, and 90 degrees C for 20-120 min at each temperature. The majority of the peaks increased in size as the temperature and time increased. Optimum conditions were established as preheating at 80 degrees C for 30 min followed by analysis on a packed column of 8% Poly MPE on Tenax GC with the temperature programmed from 50 to 200 degrees C at 10 degrees/min. Coefficients of variation for major peaks ranged from 8.3 to 14.7%. These results were compared with those obtained with a capillary column analysis of samples preheated at the same conditions. Cooked and stored chicken patties, pretreated with different levels of sodium tripolyphosphate, were analyzed by the thiobarbituric acid (TBA) method and the headspace GC technique. Significant positive correlations were obtained between TBA numbers and the areas of 3 major peaks of the headspace profiles, indicating the applicability of the rapid headspace GC method for the determination of oxidative changes in chicken meat.

Content of selected nonprotein components in poultry bone residue

The content of selected water soluble vitamins, minerals, and cholesterol in two types of poultry bone residue was evaluated. Bone residue from skinless input materials contained slightly, although significantly, more calcium, phosphorus, and potassium than the bone residue from skin containing input materials. The former residue also contained slightly more niacin than did the latter, but the content of this and the other water soluble vitamins that were analyzed was low. The lipid material in both products contained more cholesterol than many other edible animal fats.

Thresholds and psychometric functions of the individual spondaic words

Two experiments were conducted concerning the relative intelligibility of spondaic words. In the first experiment, the 36 spondaic words typically used in clinical settings to determine the Speech-Recognition-Threshold (SRT) were presented to 20 subjects at levels ranging from 10 to 28 dB SPL. The percentage of persons able to repeat each word was plotted as a function of decibel sound-pressure level to determine (a) the sound-pressure level necessary to yield a 50% response point for each word, and (b) the rate at which each word became intelligible, for example, the slope of the psychometric function. By these two criteria 15 words were found to be homogeneous. In the second experiment, SRTs were obtained on 24 subjects with the full list of 36 words and with the 15 spondaic words that were homogeneous with respect to the sound-pressure level necessary for a 50% correct response level and the rate of intelligibility growth. The results demonstrate that the two groups of spondaic words yield equivalent SRTs. The data suggest that an SRT may be determined with 15 spondaic words, which is as valid and accurate as the SRT determined with the entire list of 36 words.

Epidermal growth factor and insulin cause normal chicken heart mesenchymal cells to proliferate like their Rous sarcoma virus-infected counterparts

Normal chicken heart mesenchymal cells at low culture density are proliferatively quiescent in a physiological culture medium containing heparinized, heat-inactivated, chicken plasma at 10%. Rous sarcoma virus-infected chicken heart mesenchymal cells, on the other hand, proliferate maximally in this same medium, undergoing a 60-fold increase in cell number during 4 days of exponential growth. When normal heart mesenchymal cells are cultured for 4 days in the presence of epidermal growth factor at 1 micrograms/ml they undergo a 16-fold increase in number, with graded responses to lower concentrations of the factor. In the presence of insulin at 10 micrograms/ml, normal heart mesenchymal cells multiply by a factor of 3 over a 4-day period. The addition of epidermal growth factor (1 microgram/ml) and insulin (10 micrograms/ml) to cultures of normal chicken heart mesenchymal cells causes these cells to proliferate at a rate comparable to that of their RSV-infected counterparts.

Effects of acetylsalicylic acid on speech discrimination

Speech discrimination scores were obtained in quiet and against a background of competing noise for 5 persons both before and after they had ingested large doses of acetyl-salicylic acid (aspirin). The results indicate that for some persons, aspirin produces a substantial decrease in speech understanding in noise, even though there may not be a decrease in pure-tone sensitivity or speech discrimination in quiet.

A computer program for distinctive feature analysis

A computer program is described that will accomplish a distinctive feature analysis for speech misarticulations. The program, which is written in FORTRAN, is interactive in nature and is straightforward in design. It greatly facilitates the use of distinctive feature analysis in articulation training, as it reduces the time necessary to complete such an analysis from several hours to approximately 15 min.

Mitogenic factors present in serum but not in plasma

In culture medium containing heparinized, heat-inactivated, chicken plasma, normal chicken heart mesenchymal cells do not proliferate but their Rous sarcoma virus-infected counterparts proliferate maximally. In medium containing serum derived from chicken whole blood or plasma, on the other hand, normal chicken heart mesenchymal cells proliferate actively, at similar overall rates and to similar extents. The rate and extent of normal cell proliferation are decreased by a factor of approximately 1/2 with whole blood-derived serum that is heparinized and inactivated; proliferation ceases in plasma-derived serum that is heparinized and inactivated. Heparinization and inactivation of serum does not affect the proliferation of Rous sarcoma virus-infected cells, indicating that this combined treatment eliminates a mitogenic (regulatory) rather than a supportive (nutrient) factor(s) for cell replication. We hypothesize that mitogen(s) is released from plasma protein precursors when plasma clots in the presence of formed elements of the blood or when plasma-derived serum is exposed to cultured cells; heparinization and inactivation, within the framework of this hypothesis, would render nonfunctional the plasma protein precursor(s) from which the mitogen(s) is generated. Alternatively, our data are consistent with the release of two mitogens during blood clotting, one from plasma protein precursors and the other from formed elements of the blood. We also have studied the proliferative behavior of Swiss and BALB/c 3T3 cells in whole blood-derived and plasma-derived human serum. Our studies suggest that the platelet-derived growth factor has an artifactual supportive (nutrient) role, rather than an authentic mitogenic role, in cell replication.

The intelligibility of whitened and amplitude compressed speech in a multitalker background

This experiment determined the effects of amplitude compression on speech intelligibility when both a target speech signal and a competing message were whitened and amplitude compressed. The target CNC discrimination words were electrically mixed with a competing message composed of five talkers. This composite signal was presented to normal hearing subjects in four ways: unmodified, whitened, whitened pplus 3:1 amplitude compression and whitened plus 10:1 amplitude compression. Discrimination functions were obtained for the CNC material by varying the signal-to-competition ratio. The unmodified and whitened speech yielded comparable discrimination functions, but reduced discrimination scores were obtained with the whitened lus compressed speech. However, the reduction in speech discrimination for the whitened plus compressed speech was slight and was most evident when the target signal and the competing background were at the same intensity.

Failure to demonstrate antigonadotrophic activities of arginine vasotocin in the mouse

Arginine vasotocin (AVT) has previously been proposed to be a pineal hormone which reduces reproductive competency in mammals. The effects of AVT on the growth of immature reproductive organs of the mouse have been studied using blind study techniques. Evidence is presented which fails to support the proposed role of AVT as a mammalian antigonadotrophin.

Effects of whitening and peak-clipping on speech intelligibility in the presence of a competing message

The purpose of this experiment was to determine the effects of peak clipping on speech intelligibility when both a target speech and a competing message were simultaneously peak-clipped. A competing message composed of 5 talkers was electrically mixed with CNC discrimination words. This composite signal was presented to normally hearing subjects in three ways: unmodified, whitened, and whitened and peak-clipped. Discrimination functions were obtained for the CNC material by varying the signal-to-competition ratio. Under these conditions, essentially identical discrimination functions were yielded by the unmodified and whitened speech, whereas substantially reduced discrimination scores were obtained with the whitened/clipped speech. These results would suggest that speech intelligibility is reduced by whitening and peak clipping when more than one talker is present. This is true even though earlier studies have shown that whitening and peak clipping do not reduce speech intelligibility when only a single talker is present. Such a finding has implications for wearable amplification.

The intelligibility of whitened and peak clipped speech

Consonant-nucleus-consonant monosyllabic words were filltered such that each spectral component had equal energy (i.e., "whitened") and peak clipped in one of four ways: minimal, 20, 30, and 40 dB of clipping. In addition, unmodified consonant-nucleus-consonant words were used as stimuli. These different types of sppech were presented to 20 persons with normal hearing at various sensation levels. The results indicate that whitening and peak clipping do not substantially degrade speech intelligibility. In fact, under some conditions whitening and peak clipping may slightly enhance intelligibility.

Time-intensity trading functions for selected pure tones

A substantial number of investigations have examined the ability of the auditory system to trade time for intensity on a lateralization task. Most of these investigations, however, have employed clicks and noise bursts as stimuli with interaural disparities between onset times. Consequently, there is a lack of quantitative data for time-intensity trades where pure tones that had identical onset times but disparate phase were employed as signals. For this reason we employed sinusoids ranging from 200 to 2000 Hz and determined the extent to which the intensity of one signal must be decreased to achieve a midline image when interaural phase disparities of 0 degrees to 360 degrees were imposed between the binaural signals in 30 degree increments. The time-intensity trading functions yielded in this experiment demonstrate that (1) not unexpectedly, the largest time-intensity trades were accomplished for the lower frequencies; (2) the maximum time-intensity trade for each frequency occurred at interaural phase disparities of 90 degrees and 270 degrees; and (3) when the low-frequency tones were 180 degrees out of phase, essentially the same intraaural intensity relationship was required to achieve midline as was needed for the 0 degree interaural phase condition.