Imaging and Staging of Endometrial Cancer.

Endometrial carcinoma is the most common female pelvic malignancy in the United States. Although endometrial cancer is staged according to the International Federation of Gynecology and Obstetrics surgical system, early and accurate diagnostic assessment of disease status of gynecologic malignancies is important for optimal treatment planning and outcome prediction. Preoperative imaging may assist in evaluation of local extent and detection of distant metastatic disease guiding the optimal course of treatment. Several imaging techniques such as transvaginal ultrasound, computed tomography, and magnetic resonance imaging have been used as tools for preoperative staging of endometrial cancer. Positron emission tomography/computed tomography and more recently, positron emission tomography/magnetic resonance imaging have also been used in the management of endometrial cancer. Cross-sectional imaging, especially MRI, may detect gross myometrial invasion or extension of tumor to the cervical stroma which can alter management. Imaging studies can also evaluate the presence of lymph nodal involvement, and detect local and distant metastatic disease at diagnosis. Additionally, imaging also plays a role in the monitoring of treatment and surveillance of the patients for detection of early recurrent disease. In this article, we will review the imaging and staging of endometrial cancer.

Uterine Carcinosarcomas.

Uterine carcinosarcoma (UCS) is a rare and aggressive variant of endometrial cancer, distinguished by its containment of both epithelial and sarcomatous elements. This article reviews the epidemiology, pathologic classification and staging of UCS, along with the typical findings seen on different imaging modalities. Prognosis and therapies will also be discussed.

Primary vaginal cancer: role of MRI in diagnosis, staging and treatment.

Primary carcinoma of the vagina is rare, accounting for 1-3% of all gynaecological malignancies. MRI has an increasing role in diagnosis, staging, treatment and assessment of complications in gynaecologic malignancy. In this review, we illustrate the utility of MRI in patients with primary vaginal cancer and highlight key aspects of staging, treatment, recurrence and complications.

Tenderness enhancement of beef from Bos indicus and Bos taurus cattle following electrical stimulation.

High voltage electrical stimulation (1130 V peak, 14.28 bidirectional half sinusoidal pulses/s) or low voltage stimulation (45 V peak, 36 alternating square wave pulses/s) was used on cattle: (1) low voltage stimulation applied for 10 or 40 s with fast and slow chilling or high voltage stimulation for 60 s with normal chilling, applied to 100% Bos taurus cattle, (2) low voltage stimulation (40 s) and high voltage stimulation (60 s) with normal chilling applied to mixed Bos indicus and B.taurus cattle, (3) high voltage stimulation (54 s) with normal chilling applied to B. taurus and B. indicus cattle of 0-100% B. indicus composition, and (4) high voltage stimulation (60 s) applied to 100% B. taurus and 100% B. indicus cattle. All stimulation parameters enhanced the tenderness of steaks from M. longissimus thoracis et lumborum (LTL) aged at 1°C up to 28 days compared with non stimulated LTL. Short low voltage stimulation of 10s was marginally more effective than no stimulation and longer durations of 40s were very effective and high voltage stimulation was most effective. The shear force values for non stimulated B. indicus LTL are much greater than for B. taurus, but following high voltage stimulation LTL of B. indicus were similar to B. taurus and all had lower shear force values than from non stimulated carcasses. Thus adequate electrical stimulation removes any toughness of LTL related to B. indicus genetic composition.

Modelling muscle energy-metabolism in anaerobic muscle.

A mathematical model of anaerobic muscle energy-metabolism was developed to predict pH and the concentrations of nine muscle metabolites over time. Phosphorous-31 Nuclear Magnetic Resonance was used to measure time-course data for some phosphate metabolites and pH in anoxic M. semitendinosus taken from three slaughtered sheep. Muscles were held at 35 degrees C during the experiment. Measurement commenced 25 min post mortem and concluded before rigor mortis. The model was fitted to these data within experimental error, by simultaneously varying model parameter values and initial substrate concentrations. The model was used to simulate the period from death until metabolic activity ceased, in order to predict the different stages of metabolic response to anoxia. The model suggested that alkalinisation would occur in all three muscles in the first few minutes after the onset of anoxia, followed by a steady decline in pH. For two of the muscles this decline continued until rigor, with final pH values of 5.60 and 6.07. For the other muscle, pH reached a low of 5.60 near rigor but then increased to a final value of 5.73. A rise in pH after rigor has been observed but not previously explained in the literature. The modelling results suggest it was caused by the alkalising effect of adenosine monophosphate deamination being greater at low pH than the acidifying effect of inosine monophosphate dephosphorylation.

Pre-slaughter stress arising from on-farm handling and its interactions with electrical stimulation on tenderness of lambs.

The effect of electrical stimulation of lamb carcasses (n=269) or its absence (n=257) on shear force of m. longissimus thoracis et lumborum (LT) was monitored during ageing in pasture-fed merino lambs (n=526). The lambs were slaughtered on four different days allowing durations of between one to 10 days of recovery from pre-slaughter handling (yarding, weighing and crutching) that affected ultimate pH (pH(u)). The right LT was removed 20-40min post-slaughter, tightly-wrapped in cling film (prevents the muscle cross-section increasing and thus minimising shortening) and rapidly cooled to 15°C to enter rigor mortis and age. At 0, 4, 24 and 72h post-slaughter, pH measurements and samples for shear force measurement were taken. Pre-slaughter handling had a significant negative effect on pH(u) and several days recovery were required for pH(u) to reach values associated with optimal meat quality as reflected by pH(u). Lambs with one and three days recovery (no significant difference between them) had a pH(u)>5.7 in 50% of the muscles and 19.4%>pH(u) 5.8. Whereas, in lambs with 8-10 days recovery (no significant difference between them), only 8% had a pH(u)>5.7 and 3.1%>pH(u) 5.8. Within each slaughter day electrically stimulated lambs were always more tender than non-stimulated lambs. For non-stimulated muscles at 72h, shear force values >40N occurred for 11.2% of the muscles: for electrically stimulated muscles at 72h, shear force values >40N occurred for 1.9% of the muscles. The rates of tenderisation were slower for intermediate pH(u) values resulting in higher shear force values at all ageing durations. With ageing at 72h for intermediate pH(u), non-stimulated muscles (n=38) 17.64% were >40N and for stimulated muscles (n=34), 7.9% were >40N.

The relationship between postmortem urinary catecholamines, meat ultimate pH, and shear force in bulls and cows.

We investigated the relationship between stress responsiveness and meat quality in cattle. The cattle were 16-19-month-old Mixed (n=37, 303 kg) or Non-mixed (n=23, 279 kg) Friesian bulls and Friesian cull cows (1.5-7 years) that were classified Unfinished (n=133, 195 kg) or Finished for 3 months (n=34, 252 kg). A portion of m. longissimus lumborum (LL) muscle was obtained from consecutive animals for a single days slaughter of 227 cattle processed through a hot boning plant. Catecholamines were obtained from bladder urine. Ultimate pH, lactate, glycogen, glycolytic potential and representative sarcomere lengths were determined from 20-h muscle samples. Shear force measurements were from meat aged at 15 °C for 20 and 90 h. Urinary noradrenaline was similar between Mixed (14.86 ng/µmol creatinine) and Non-mixed bulls (14.07 ng/µmol creatinine) and Finished cows (15.24 ng/µmol creatinine) and elevated in the Unfinished cows (22.28 ng/µmol creatinine). Urinary adrenaline was higher in Mixed bulls (9.5 ng/µmol creatinine) than Non-mixed bulls (5.7 ng/µmol creatinine) and higher in both Unfinished cows (16.67 ng/µmol creatinine) and Finished cows (14.19 ng/µmol creatinine). For bulls that are growing well on-farm, with a only short period of fasting prior to slaughter, pH(u) is a good predictor of meat tenderness. In this situation, stressors that lower muscle glycogen pre-slaughter can have a significant effect on meat shear force, and individual animals with elevated urinary adrenaline were the most susceptible. However, in the case of cows, adrenaline responses are not necessarily associated with glycogen depletion and pH(u) is less affected than for bulls. Furthermore, the ability of meat to tenderise fully, related to reduced proteolytic turnover, is reduced in nutritionally compromised animals such as the Unfinished cows.

The biochemical and physical effects of electrical stimulation on beef and sheep meat tenderness.

Application of electrical stimulation in the sheep and beef processing industry has been erratic around the world and this may reflect an incomplete knowledge of how to optimise the technology. Although it is well established that stimulation increases the rate of post-mortem glycolysis, other biochemical and biophysical effects have been implicated with the use of this technology. This review seeks to examine the current theories about the effect of stimulation on post-mortem muscle. The classical view that stimulation prevents muscle from shortening excessively during rigor development has been expanded to include the possibility that it also results in physical disruption of muscle structure. The interaction of these effects with the acceleration of the rate of proteolysis through activation of the calpain protease system has not been comprehensively reviewed in the past. Thus there are two mechanisms which could explain the effect of stimulation on tenderisation, reduced 'cold-induced' shortening and alteration of protein structure. A secondary effect is the enhancement of the rate of proteolysis stimulated by release of Ca (2+) at a higher temperature. As a result of this review we highlight several areas that may prove fruitful for further research. The challenge for further development of electrical stimulation systems is optimisation of the activation of the enzyme systems in parallel with manipulation of chilling regimes so as to ensure rigor mortis is achieved at temperatures which minimise shortening. These optimal temperatures largely established at a fixed incubation temperature for detached muscle may be different when measured in intact carcasses. The potential of regional stimulation of sections of the carcass to achieve this outcome is worthy of study given the different fibre composition of muscles and temperature gradients. In addition, to ensure that appropriate amounts of energy are applied to individual carcasses, development of self-response stimulation units, which are able to determine carcass resistance and apply appropriate durations or strengths of stimulation is worthy of future research. This would lead to more effective electrical stimulation practices.

The effect of nutritional supplements on growth rate, stress responsiveness, muscle glycogen and meat tenderness in pastoral lambs.

Nutritional supplements and a magnesium bolus and were used in lambs in a 2×2 factorial design to investigate the effect on growth, preslaughter stress measurements, muscle glycogen, and meat quality. In total, 64 Perendale lambs were used (32.7±0.53 kg, mean±SEM). Feed supplemented animals received 150 g feed pellets day(-1) in addition to pasture grazing, and this increased growth from 183 to 207 g day(-1). Mean delivery of Mg from the boluses was 0.17 g day(-1) for 28 days, with no effect on growth rates, or any other of the variables measured. Urinary noradrenaline, adrenaline and cortisol did not differ between groups in the immediate pre-slaughter period. The meat ultimate pH was not different between groups and had a mean range of 5.47-5.53. Muscle residual glycogen did not differ between groups and had a mean range of 42-43 mmol kg(-1). Finally there were no differences in shear force values at all ageing times. The final shear force value of 2.5 kg F after 72 h ageing at 15 °C was a low value representing tender meat. These studies indicate that if nutrition is adequate and stress levels are low, there are no differences in meat tenderness of pasture fed lambs compared with those having feed supplements to increase growth rate.

Effect of rigor temperature on muscle shortening and tenderisation of restrained and unrestrained beef m. longissimus thoracicus et lumborum.

Pairs of muscularis longissimus thoracicus et lumborum (LTL) from young bulls were removed within 1h of slaughter. Small portions of the muscles were placed in a rigormeter to continously follow the isometric tension and isotonic shortening developed, at constant temperatures of 15, 20, 25, 30 and 35°C, as the muscle went into rigor. The bulk LTL was placed in water baths at the same temperature. One of the bulk pairs was tightly restrained by wrapping, to reduce muscle shortening, the other was unrestrained free to shorten. For the bulk samples, shear values were measured using a Warner-Bratzler instrument (1, 7 and 14 days post mortem), and sensory attributes were measured using a sensory panel (7 and 14 days post mortem). Minimum tension and shortening occurred at 15°C. The activation energy for the muscle shortening process was larger than for the isometric tension process. This indicates that the isometric tension data, collected during rigor, does not solely reflect muscle shortening. Thus, a counteracting process that decreases the tension response, most likely ageing is simultaneously detected. Meat that went into rigor at 15°C had least shortening and was always more tender than meat going into rigor at higher temperatures. For meat entering rigor at temperatures higher than 15°C, restraining of the muscle by wrapping, significantly (p<0.05) decreased the amount of muscle shortening and resulted in an improved meat tenderness (p<0.001). It was also observed that at rigor temperatures higher than 15°C the meat tenderness is affected negatively by a reduced ageing capacity. It therefore appears that muscle shortening and enzyme activity both affect tenderness and that both are highly affected by rigor temperature and have the greatest beneficial effect at a rigor temperature of 15°C.

The effects of non-vacuum packaging systems on drip loss from chilled beef.

This study investigated drip loss in chilled beef (hot-boned m. longissimus lumborum (LL)) under conventional packaging systems, in which a vacuum is applied, and non-vacuum packaging systems. The use of vacuum during the packaging process (vacuum packaging, CO(2) atmosphere packaging) was associated with increased drip. Drip was lower in heat-shrunk vacuum packaging than in non-shrunk vacuum packaging. A slow vacuum onset had no effect on drip formation, or may have increased it. The extent of pressure reduction (vacuum; range 0-1 atm) did not significantly affect drip formation, although the standard vacuum pressure (0 atm) tended to cause more drip loss than higher pressures. The three non-vacuum anaerobic packaging systems tested were: flushed with carbon dioxide without the pressure being reduced below atmospheric (Flush), or the same system with no CO(2) flush but a proprietary oxygen absorber added (Scavenger), or a combination of both (Flush/Scavenger). Storage was at -1.5 °C for up to 20 weeks. The Flush and Flush/Scavenger systems had considerably lower drip loss than the CAP standard system (6.4%, 6.5%, and 9.1% respectively); the Scavenger system had the lowest drip loss (5.2%). Drip losses generally increased with storage period, irrespective of packaging system. All non-vacuum packaging systems except the Flush system had very low oxygen levels (<0.l% v v ). The Flush system had considerably higher levels of oxygen (0.9%) with associated browning of meat samples. All packaging systems gave a hygienic shelf-life of at least 16 weeks. At 16 weeks, microbial numbers were highest (5 × 10(6)) in the Scavenger system. The meat from all packaging systems was acceptable to taste panels even after 16 weeks of storage at -1.5 °C. There were no significant differences between any of the packaging systems for any of the sensory attributes tested. The packaging systems with the best all round performance were the Flush/Scavenger and the Scavenger systems, depending on the storage-life required.

Changes in lactic acid levels during thawing of lamb chops.

Loins from 20 lambs with an ultimate pH ranging from 5.5 to 6.4 were frozen and stored at -20 °C, then thawed at + 3 °C. During thawing, muscle (m. longissimus lumborum) lactate was measured in samples taken when the meat temperature reached -20, -5, -2, 0, and + 2 °C. At -5 °C, muscle lactate concentration was similar to that at -20 °C, but at -2 °C lactate levels were double those at -20 °C. As the temperature increased to +2 °C lactate concentrations fell from their -2 °C level. Low pH (5.5-5.6) and intermediate pH (5.7-6.1) meat at +2 °C had a higher lactate level than at -20 °C, with the greatest difference occurring in the low pH group (5 mmol lactate kg equating to approximately 0.05 pH unit increase). High pH meat (6.2-6.3) had similar lactate levels at -20 °C and +2 °C. These results demonstrate the importance of measuring the pH of frozen meat immediately rather than thawing the meat before measurement, and also show that meat pH may change on thawing, depending on the ultimate pH of the sample.

Measurement of nitric oxide and the effect of enhancing or inhibiting it on tenderness changes of meat.

Possible roles of the cellular messenger nitric oxide (NO) in post-mortem meat ageing were investigated in bull m. longissimus lumborum. Both enhancement and inhibition of NO activity had positive and negative effects, respectively, on early rates of ageing. These also correlated with direct measurements of NO in the meat samples. However, by 8 days of storage, the tenderness was not significantly different to non treated meat samples.

Social behaviour in sheep relates to behaviour and neurotransmitter responses to nociceptive stimuli.

Sheep in the field display differences in social behaviour. These differences allow a division into three social groups with distinct behavioural occurrences and frequencies. The behavioural and neurotransmission responses of each of these groups to aversive stimuli were compared. Behavioural responses were seen to both forelimb electric shocks and thermal heating of the nose in all groups. These responses changed with stimulus repetition in a group-dependent manner. Microdialysis probe studies of neurotransmitter release in the somatosensory cortex indicated neurotransmitter responses to stimuli in all animals that varied with both animal group and stimulus repetition. Group 1 animals, aggressive and socially active, showed increases in gamma amino-4-butyric acid (GABA) with initial stimulus presentation; this increased with stimulus repetition. Behavioural responses to the stimuli decreased with repetition and nonstimulus-related behaviours, during the course of the experiment, increased. Both of these appeared dependent upon GABA. Group 2 animals, moderately aggressive and socially active, released opioid-like peptides (OLP) upon initial exposure to stimuli but, with repetition, switched to using GABA. Group 3 animals, nonaggressive and socially inactive, released OLP with initial and repeat stimuli. In groups 2 and 3, both GABA and OLP appear to reduce stimulus-related behaviour, but OLP appeared to also reduce nonstimulus-related behaviour and GABA increased these. Changes were independent of animal liveweight. Glutamate was released in response to stimuli in all 3 groups and, with repetition, fell in groups 1 and 2 but increased in group 3. An animal's social behaviour and status may predict its response to a stimulus.

Changes in the release of amino acid neurotransmitters in the brains of calves and sheep after head-only electrical stunning and throat cutting.

In calves aged two to five months, throat cutting resulted in an increase in the concentration of the amino acid neurotransmitters glutamate and aspartate in the brain. Electrical head-only stunning by itself also increased the concentrations of these two neurotransmitters. The levels induced by stunning resulted in a seizure state characterised by epileptiform-like activity in the electroencephalograph. Combing head-only stunning with throat cutting within 10 seconds of the stun had a synergistic effect upon glutamate and aspartate, increasing their concentration by a greater amount and more quickly than either procedure on its own. An irreversible loss of brain function also occurred more quickly than after throat cutting alone. The administration of glutamate and aspartate receptor antagonists before the throat cutting lengthened the time to the loss of brain function in a dose dependent manner. Similar changes were observed in sheep but they occurred much more quickly than in cattle.

The effects of the ultimate pH of meat on tenderness changes during ageing.

A range of ultimate pH (pH(u)) values, from 5.4 to 7.2, was produced in the m. longissimus thoracicum et lumborum (LD) of 55 sheep by subcutaneous injections of adrenaline, or by injection and subsequent exercise. The rate constant of ageing for each of 47 animals was calculated from shear force measurements, taken at intervals for up to 5 days from the LD held at 12 dgC. The relationship between the ageing rate and pH(u) could be adequately described by the equation rate constant (k) = 4.109 - 1.349(pH) + 0.1111(pH)(2); r(2) = 0.707, with a minimum rate constant at pH 6.07. The loin muscles from eight carcasses were selected to determine the effects of ultimate pH on the initial, unaged toughness value. Calpain activity was inhibited by intramuscular injection of ZnCl(2) dissolved in saline, and the muscles were aged at 10-12 °C on the carcass for up to 6 days. At all values of pH(u) (5.4-6.7), tenderness as measured by shear force were equivalent, from which it was concluded that the initial toughness of unaged lamb was not affected by pH(u). In the contralateral, untreated muscle, ageing was measured using both shear force measurement and changes in the myofibrillar fragmentation index (MFI). After 1 day, the intermediate pH range (5.8-6.2) has the highest shear force and the lowest fragmentation index value. However, in contrast to the shear force values, the ultimate MFI value in aged muscle was lowest in the high pH(u) range (6.4-6.7; minimum value at 6.4). The highest fragmentation values were found at the low pH(u) range. These observations suggest that pH(u)-related tenderness differences in meat result from different rates of ageing in the post rigor period, and therefore that these differences disappear following a sufficient ageing period. The slowest rate of tenderization measured on cooked meat was observed at pH(u) values around 6.07, but the least fragmentation of raw meat was observed at pH(u) values around 6.4, a difference of almost 0.33 pH unit.

The basal toughness of unaged lamb.

Identification of the commencement of aging in relation to the rigor process was determined on lamb loin muscles by injecting a zinc-TRIS solution, which inhibits meat aging, into the muscle over the period when the pH was falling. Aging was evaluated by measuring the tenderness of cooked meat samples using a MIRINZ tenderometer. When zinc was injected into muscle above pH 6·5, the sarcomeres shortened and the cooked meat had an average shear force of 19 kgF (shear force is the force required to shear through at 1 cm cross-section sample). When sinc was injected into the muscle at pH values below 6·5 the sarcomeres did not shorten, and down to the ultimate pH, the shear force remained at approximately 15 kfF. Aging did not take place pre-rigor. The same relationships occurred for electrically stimulated muscle. The data indicate that the basal shear-force value of lamb loin prior to aging, i.e. the basal toughness level, is 15 kgF.

The effect of electrical head-only stun duration on electroencephalographic-measured seizure and brain amino acid neurotransmitter release.

Effective electrical head-only stunning produces a seizure-like state followed by a period of analgesia seen in animals allowed to recover. Passing of a 1·0 A current (50 Hz, 500 V) for less than 0·2 s, through the head of a sheep does not produce a seizure-like state as evidenced by recorded electroencephalogram. Corresponding to this lack of seizure-like state, the release of the neurotransmitters glutamate and aspartate, in the brain, occurs to levels associated with arousal rather than seizure. At a duration of 0·2 s, the same stun parameters as above produce a seizure-like state and the release of glutamate and aspartate rises dramatically. The length of the seizure-like state, and the levels of release of glutamate, aspartate and a third neurotransmitter gamma amino-4-butyric acid (GABA), increased with stun duration until 4·0 s duration, where a peak in these parameters was seen. Stun durations of 2·0, 4·0, 8·0 and 12·0 s all produce similar effects. At a duration of 20 s, however, the length of the seizure-like state and the release of neurotransmitters is less than at shorter stun durations. For welfare purposes a head-only electrical stun, of 1·0 A, at a duration as low as 0·2 s produces unconsciousness and analgesia to subsequent slaughter procedures. However, maximum welfare benefits appear attainable at durations between 2·0 and 20·0 s.