The surgical burden of breast disease in KwaZulu-Natal province.

BACKGROUND: The current surgical workload assessments in KwaZulu-Natal (KZN) are inadequate to inform strategies to improve surgical services. Breast diseases have a well-defined spectrum and surgical treatment options, analysis of which could guide health policy in the field. This project aimed to quantify and analyse the operative workload for breast pathology in KZN. METHODS: A retrospective review of breast-related operations conducted at public sector hospitals in KwaZulu-Natal province between 1 July and 31 December 2015 was undertaken. Data was collected from theatre operative registers and manually categorised as follows: sepsis, benign pathology, malignant pathology, and by hospital, according to geographic location, and complexity of care to determine factors to improve the service for breast care in the province. RESULTS: In the 6-month study period, 13 282 general surgical procedures were performed of which 776 (5.8%) were breast-related operations. There were 372 (47.9%) operations for breast sepsis, 140 (18%) for benign breast lesions, 17 (2.2%) for cosmetic indications and 27 (3.5%) for diagnostic procedures. There were 223 (28.7%) procedures for nonbenign disease: 21 (2.6%) wide local excisions (WLE), 203 (26.2%) mastectomies of which 161 (72.2%) mastectomies had an axillary lymph node dissection and 26 (11.7%) were performed as onco-plastic procedures. Hospitals in the Durban and Pietermaritzburg metropolitan areas performed 75% of the breast-related procedures. The majority (69.6%) of sepsis-related procedures were performed at secondary/regional facilities, while 58.3% of non-benign breast surgeries were performed at tertiary and quaternary centres. CONCLUSION: Breast sepsis accounts for almost 50% of the surgery and is mainly dealt with at hospitals above district level. One-third of breast surgery in KZN province is for non-benign disease. There is a paucity of breast-conserving surgery. Elucidation of these observations can guide improvement in the provincial breast care service.

Alpha-tocopherol acetate and alpha lipoic acid may mitigate the development of wooden breast myopathy in broilers at an early age.

1. The objective of this study was to identify the effects of the antioxidant alpha-tocopherol acetate (ATA) and alpha lipoic acid (ALA) which have anti-inflammatory effects on developmental onset, severity and the progression of wooden breast (WB) based on Pectoralis major (P. major) muscle morphology and expression of genes associated with WB during the first three weeks post-hatch.2. A total of 160 newly hatched Ross 708 broiler chicks were randomly assigned in a replicated trial to either a control group or three dietary treatments (ATA 160 mg/kg feed, ALA 500 mg/kg feed or in combination).3. Microscopic changes associated with WB began at one week of age in all groups. The ATA acetate and ALA fed in combination decreased WB severity at two weeks of age (P = 0.05) and ATA alone or in combination reduced severity at three weeks of age compared to the control group (P = 0.05). Expression of myogenic determination factor 1 and peroxisome proliferator-activated receptor gamma was reduced in all dietary treatments compared to the control at three weeks of age (P ≤ 0.05), which suggested reduced muscle degeneration and lipid deposition.4. ATA and ALA fed both independently and in combination had a positive effect on mitigating WB severity microscopically as early as two weeks of age.

Incubation temperature and time of hatch impact broiler muscle growth and morphology.

The adult myogenic population of stem cells, called satellite cells, initially develop in late-term embryos. Satellite cells are the only myogenic cell that repair damaged myofibers and increase post-hatch growth. The objective of the current study was to determine if incubation temperatures and time of hatch impact growth and pectoralis major (p. major) muscle morphology. Eggs were incubated at a constant 37.8°C; however, from d 14 to 18, the eggs were subject to 39.5°C for 0, 3, or 12 h per day. Chicks were divided into early, mid, or late hatch groups based upon the time they emerged from the shell. Growth and feed efficiency were measured throughout the 63-day trial, while meat quality and muscle morphology were evaluated at the time of processing. The chicks incubated at an increased temperature for 12 h per d had reduced (P < 0.01) body weights throughout the trial compared to the 3 h treatment and control. The early hatch broilers were heavier (P < 0.01) at 63 d compared to mid and late hatch broilers. Chicks from the 12 h incubation treatment had an increased (P = 0.01) gain to feed ratio compared to the control. Broilers from the 12 h incubation treatment had lower (P < 0.01) p. major weights compared to the 0 and 3 h treatments. Early hatch broilers had heavier p. major weights (P < 0.01) compared to mid and late hatch groups. The 12 h incubation treatment also reduced the number of broilers with moderate to severe myopathic attributes compared to the control. Similarly, there were fewer late hatch birds with fibrotic and necrotic p. major muscles compared to the early hatch group. Together, these data demonstrate that altering incubation temperature is a feasible management strategy to improve muscle morphology without negatively impacting meat quality parameters.

Influence of temperature and growth selection on turkey pectoralis major muscle satellite cell adipogenic gene expression and lipid accumulation.

P. MAJOR: Immature poults have an inefficient thermoregulatory system, and therefore extreme ambient temperatures can impact their internal body temperature. Satellite cells, the only posthatch myonuclei source, are multipotential stem cells and sensitive to temperature. Selection for faster-growing, high-yielding birds has altered satellite-cell properties. The objective of the current study was to determine how temperature affects adipogenic properties of satellite cells isolated from the pectoralis major ( ) muscle of Randombred Control line ( ) and F line turkeys selected only for increased 16-wk body weight from the RBC2 line. Satellite cells were cultured at 2°C incremental temperatures between 33 and 43°C and compared to cells cultured at the control temperature of 38°C to ascertain temperature effects on lipid accumulation and expression of adipogenic genes: CCAAT/enhancer-binding protein-ß ( ), peroxisome proliferator-activated receptor-γ ( ), and stearoyl-CoA desaturase ( ). During proliferation, the amount of quantifiable lipid in both F and RBC2 satellite cells increased at temperatures above 38°C ( P <  0.01) and decreased at temperatures below 38°C ( P < 0.01). Above 38°C, RBC2 satellite cells had more lipid ( P = 0.02) compared to the F line, whereas there were few differences between lines below 38°C. At 72 h of proliferation, expression of C/EBPß , PPARγ , and SCD decreased ( P ≤  0.02) as temperatures increased from 33 to 43°C in both cell lines. During differentiation expression of C/EBPß increased ( P <  0.01) as temperatures increased from 33 to 43°C in both cell lines. In F line satellite cells, PPARγ expression decreased ( P <  0.01) with increasing temperatures during differentiation, whereas there was no linear trend in RBC2 cells. During differentiation expression of SCD increased as temperatures increased ( P <  0.01) in RBC2 cells, and there was no linear trend within the F line. Results from the current study suggest that environmental temperature can affect p. major satellite cellular fate; however, selection for increased body weight had little impact on these cellular responses.

Spatial influence on breast muscle morphological structure, myofiber size, and gene expression associated with the wooden breast myopathy in broilers.

The wooden breast (WB) myopathy is identified by the palpation of a rigid pectoralis major (p. major) muscle and is characterized as a fibrotic, necrotic p. major disorder in broilers. The objective of the current study was to determine spatial morphological and gene expression differences at 4 locations within WB affected muscle from different genetic lines. Morphology was evaluated in 2 broiler lines expressing the WB myopathy (Lines A and B) and a line without WB (Line C) at 3 ventral locations and one anterodorsal location in the p. major muscle. In WB affected muscle of Line A, fibrosis was greatest in the anterior locations of WB affected muscle. In Line B muscle, fibrosis was greatest in the anteroventral region and minimal in the anterodorsal or posterior regions. Average p. major myofiber diameter was 30% larger in Lines A and B compared to Line C. However, in Line A there were no differences between the percentage of large fibers (diameter >70 µm) in unaffected and WB affected muscles at any sampling region. The percentage of small fibers (diameter <10 µm), likely small regenerating fibers, and expression of myogenic determination factor 1 (MYOD1) and myogenin were increased in Line A WB affected muscle compared to unaffected muscle. In Line B, the percentage of small fibers and MYOD1 expression in WB affected muscle was not different from unaffected muscle. Connective tissue organization within WB affected muscle was also different in Lines A and B, which may be attributed to decorin, a proteoglycan that mediates collagen crosslinking, growth factor signaling, and cell growth. Decorin expression was increased at all locations within Line A. However, in Line B decorin was increased only in the fibrotic regions of the p. major. The compiled results provide evidence that the WB myopathy is not uniform throughout the entire p. major muscle and the anterior end of the p. major muscle was more affected by the condition.

Temperature effect on proliferation and differentiation of satellite cells from turkeys with different growth rates.

Poultry selected for growth have an inefficient thermoregulatory system and are more sensitive to temperature extremes. Satellite cells are precursors to skeletal muscle and mediate all posthatch muscle growth. Their physiological functions are affected by temperature. The objective of the current study was to determine how temperature affects satellite cells isolated from the pectoralis major (p. major) muscle (breast muscle) of turkeys selected for increased 16 wk body weight (F line) in comparison to a randombred control line (RBC2) from which the F line originated. Pectoralis major muscle satellite cells were thermally challenged by culturing between 33°C and 43°C to analyze the effects of cold and heat on proliferation and differentiation as compared to control temperature of 38°C. Expression levels of myogenic regulatory factors: myogenic differentiation factor 1 (MYOD1) and myogenin (MYOG) were quantified by quantitative polymerase chain reaction (qPCR). At all sampling times, proliferation increased at a linear rate across temperature in both the RBC2 and F lines. Differentiation also increased at a linear rate across temperature from 33 to 41°C at all sampling times in both the F and RBC2 lines. Satellite cells isolated from F line turkeys were more sensitive to both hot and cold temperatures as proliferation and differentiation increased to a greater extent across temperature (33 to 43°C) when compared with the RBC2 line. Expression of MYOD1 and MYOG increased as temperatures increased from 33 to 41°C at all sampling times in both the F and RBC2 lines. These results demonstrate that satellite cell function is sensitive to both cold and hot temperatures and p. major muscle satellite cells from F line turkeys are more sensitive to temperature extremes than RBC2 satellite cells.

Increased prenatal IGF2 expression due to the porcine intron3-G3072A mutation may be responsible for increased muscle mass.

A SNP (IGF2 G3072A) within intron 3 of disrupts a binding site for the repressor zinc finger BED-type containing 6 (ZBED6), leading to increased carcass lean yields in pigs. However, the relative contributions of prenatal as opposed to postnatal increased IGF2 expression are unclear. As muscle fiber number is set at birth, prenatal and neonate skeletal muscle development is critical in determining mature growth potential. Therefore, the objectives of this study were to determine the contributions of hyperplasia and hypertrophy to increased muscle mass and to delineate the effect of the mutation on the expression of myogenic genes during prenatal and postnatal growth. Sows (IGF2 A/A) were bred to a single heterozygous (IGF2 A/G) boar. For fetal samples, sows were euthanized at 60 and 90 d of gestation (d60 and d90) to obtain fetuses. Male and female offspring were also euthanized at birth (0d), weaning (21d), and market weight of approximately 130 kg (176d). At each sampling time, the LM, psoas major (PM), and semitendinosus (ST) muscles were weighed. Samples of the LM were used to quantify the expression of IGF family members, myogenic regulatory factors (MRF), myosin heavy chain isoforms, and growth factors, myostatin, and . Liver samples were used to quantify and expression. At 176d, weights of LM, PM, and ST muscles were all increased approximately 8% to 14% (P < 0.01) in pigs with paternal A (A(Pat)) alleles compared with those with paternal G (G(Pat)) alleles. Additionally, total muscle fiber number in the ST at 176d tended to be greater (P = 0.10), whereas muscle fiber cross-sectional area tended to be reduced ( P= 0.08) in A(Pat) pigs compared with G(Pat) pigs. In addition to the expected 2.7- to 4.5-fold increase (P ≤ 0.02) in expression in the LM in A(Pat) compared with G(Pat) pigs at postnatal sampling times (21d and 176d), IGF2 expression was also increased (P ≤ 0.06) 1.4- to 1.5-fold at d90 of gestation and at birth. At d90, expression of myogenic factor 5 (MYF5), a MRF expressed in proliferating myoblasts, in the LM was greater (P = 0.01) in A (Pat) pigs than in G(Pat) pigs. Interestingly, at 21d hepatic expression was greater (P = 0.01), whereas expression decreased (P = 0.01) in A(Pat) pigs compared with G(Pat) pigs; however, there were no differences (P ≥ 0.18) in hepatic expression between genotypes at 0d and 176d. These data suggest that prenatal hyperplasia of muscle fibers stimulated by increased IGF2 expression may contribute to increased muscle mass of A(Pat) pigs.

Effects of the porcine IGF2 intron 3-G3072A mutation on carcass cutability, meat quality, and bacon processing.

A SNP in a regulatory region of intron 3 within the porcine IGF2 gene (IGF2-G3072A) is associated with increased lean deposition and decreased fat deposition in pigs with paternal A alleles (APat) compared with pigs with paternal G alleles (GPat). However, data regarding fresh and processed meat quality characteristics of pigs with different alleles for this polymorphism are limited. A single heterozygote (AG) boar was bred to homozygous (AA) commercial Yorkshire-cross sows producing F1 barrows and gilts with either GPat or APat. Two farrowing groups of barrows and gilts were group housed, provided ad libitum access to a diet that met or exceeded NRC nutrient recommendations throughout production, and slaughtered at 176 d (±4 d) of age. Fresh LM quality and estimated percent fat-free lean measurements were taken on the left side of carcasses, while carcass cutouts were completed with right sides. Fresh belly and bacon processing traits were characterized for only block 1 pigs. Pig was treated as the experimental unit for all analyses. Ending live weight and HCW were not affected by IGF2 allele; however, 10th rib backfat thickness was 0.41 cm less (P=0.01), loin eye area was 4.0 cm2 greater (P=0.01), and predicted fat-free lean was over 2 percentage units greater (P<0.01) in APat pigs compared with GPat pigs. Furthermore, boneless lean cuts from the shoulder, loin, and ham were heavier (P<0.05) in APat pigs compared with GPat pigs. Minolta L* value was 2.36 units greater (P=0.03) but cooking loss was 1.82 percentage units greater (P<0.01) in APat pigs compared with GPat pigs. Additionally, despite reductions in subcutaneous fat, extractable intramuscular lipid from the LM was 0.64 percentage units greater (P=0.02) in APat pigs compared with GPat pigs. Bellies were 7.17 mm thinner (P=0.01), had 7.27 cm less flop distance (P=0.05), and tended to have 1.34 units greater iodine value (P=0.09) in APat pigs compared with GPat pigs. While not statistically different (P=0.30), the magnitude of difference in slicing yield as a percentage of green weight was 1.57 percentage units between bellies from APat pigs (85.83%) and bellies from GPat pigs (87.40%). Pigs with GPat had superior belly quality that may positively impact commercial bacon production. However, pigs with APat yielded a greater amount of lean product at the expense of producing lighter LM color and increased cooking loss.

Effects of immunological castration (Improvest) on changes in dressing percentage and carcass characteristics of finishing pigs.

The objective was to determine which tissue components contributed to the reduction in carcass yield of immunologically castrated (IC) barrows when compared to physically castrated (PC) barrows. The carcass yield of an IC barrow is less than the carcass yield of a PC barrow. This has historically been attributed to the presence of testicles, but the testes have only accounted for approximately 0.25% of live weight. This experiment included PC barrows, intact males, IC barrows, IC barrows fed ractopamine hydrochloride, and gilts. When the pigs reached 15 wk old, they were weighed, assigned to treatments (intact male or IC barrow), and penned in groups of 4 pigs per pen. Pigs designated for immunological castration were given injections at approximately 16 wk old and approximately 20 wk old. Pigs were eligible for harvest 33 d after the second injection when the average weight of the pen reached 130 kg. Immunologically castrated barrows lost on average 0.7% units more live weight during transport and lairage than PC barrows, intact males, or gilts. Physically castrated barrows had a 1.43% unit advantage over IC barrows in carcass yield. The differences in yield can be attributed to differences in testicles, reproductive tract, intestinal mass, gut fill, and some visceral organs. Testicle weight accounted for a 0.28% unit reduction in carcass yield of IC barrows when compared to PC barrows. Additional reproductive tract weights accounted for differences of 0.10% units. Intestinal mass (empty large intestine, small intestine, and stomach) was 0.2% units heavier in IC barrows when compared to PC barrows. Livers from IC barrows were 200 g heavier (P < 0.05) and kidneys were 40 g heavier than the same organs in PC barrows. These 2 organs combined for a 0.15% unit difference in carcass yield between IC and PC barrows. Gut fill, testicles, reproductive tract, intestinal mass, and the liver and kidney accounted for 0.97 of 1.43% unit differences in carcass yield between IC and PC barrows. Immunologically castrated barrows had less marbling than PC barrows, but there were no other differences in pork quality parameters. Cutability differences were less than reported in previous experiments, but IC barrows still had a 1.0% unit advantage in lean cutting yield and a 0.7% unit advantage in carcass cutting yield when compared to PC barrows.

Observation of 239Pu nuclear magnetic resonance.

In principle, the spin-½ plutonium-239 ((239)Pu) nucleus should be active in nuclear magnetic resonance spectroscopy. However, its signal has eluded detection for the past 50 years. Here, we report observation of a (239)Pu resonance from a solid sample of plutonium dioxide (PuO(2)) subjected to a wide scan of external magnetic field values (3 to 8 tesla) at a temperature of 4 kelvin. By mapping the external field dependence of the measured resonance frequency, we determined the nuclear gyromagnetic ratio (239)γ(n)(PuO(2))/2π to be 2.856 ± 0.001 megahertz per tesla (MHz/T). Assuming a free-ion value for the Pu(4+) hyperfine coupling constant, we estimated a bare (239)γ(n)/2π value of ~2.29 MHz/T, corresponding to a nuclear magnetic moment of µ(n) ≈ 0.15µ(N) (where µ(N) is the nuclear magneton).

Varying the temperature of the liquid used for high-pressure processing of prerigor pork: effects on fresh pork quality, myofibrillar protein solubility, and frankfurter textural properties.

UNLABELLED: The objective was to evaluate high-pressure processing (HPP) with varying liquid (water) temperatures on pork quality and textural properties of frankfurters. HPP pressurization liquid temperatures were 15.5 °C (HPP Low) and 29.4 °C (HPP Med). Analyses were conducted using paired boneless loins and paired boneless hams. Loins were evaluated for pH, purge loss, objective color, subjective color, firmness; and changes in color after a bloom period. Eight independent batches (2 batches each of HPP Low, paired untreated, HPP Med, and paired untreated) of frankfurters were manufactured from the outside portion of the ham and the knuckle. Both HPP treatments resulted in higher (P < 0.05) ultimate pH and less (P < 0.05) purge loss of the loin. Loin tenderness was not different among either HPP treatment temperature groups when compared to untreated controls except HPP Med chops were more tender (P = 0.02) than untreated controls. Salt-soluble protein extractability of inside ham muscles was lower (P < 0.05) for both HPP treatment levels when compared to untreated controls, but was not different between the 2 HPP treatment levels. Textural properties of frankfurters were not different for either HPP treatment group when compared to its respective untreated control for any parameter except springiness. HPP Low frankfurters had lower (P = 0.10) springiness values than untreated controls. Fracturability of HPP Med samples was lower (P = 0.12) than untreated controls. Overall, HPP caused higher ultimate pH and increased water-holding capacity, but did not affect tenderness of fresh meat or textural properties of frankfurters. PRACTICAL APPLICATION: HPP can be used on prerigor pork as means to improve fresh pork quality. Loins from HPP-treated pork sides had higher ultimate pH values and less package purge loss. Tenderness values were not affected positively or negatively by HPP treatment. The high pH and water-holding capabilities of treated samples have positive implications for further processing applications. Frankfurter textural properties suggest emulsified products can be made with pressurized pork without sacrifice to the textural profile.

Muscle gene expression associated with increased marbling in beef cattle.

The objective of this study was to identify specific bovine genes expressed within skeletal muscle that are associated with intramuscular fat deposition. Twenty-eight Angus-Simmental cross steers and heifers were harvested at the University of Illinois Meat Science Laboratory. Four pairs of animals were identified based on similar adjusted backfat thickness but differing amounts of intramuscular fat within each pair. RNA was extracted from muscle samples devoid of visible fat and microarray analysis was performed. Based on this analysis, 9 genes were selected and expression was subsequently confirmed by qPCR. Expression levels of MYH3, HOXD10, MXRA8, and CASQ2 were increased in animals with high marbling, whereas levels of NPNT, MRC1, DNER, and CYPB4 were decreased in high marbled animals. The remaining gene, ACTN2 was determined to be a false positive and was, therefore, excluded from further study. Despite the positive results of the preliminary study, associations between gene expression and intramuscular fat content did not extend to the larger population of cattle. A significant negative association existed between expression of MRC1 and marbling level (P = 0.04). Therefore, this study was unable to identify a particular skeletal muscle gene set whose expression correlated well with marbling levels in the larger population of beef cattle.

Effects of increasing lysine on further processed product characteristics from immunologically castrated male pigs.

The objective of this experiment was to determine if increasing lysine in the diets of immunologically castrated (IC) male pigs would affect further processed product characteristics when compared with physical castrates or entire males. Raw materials for this experiment were derived from a previous experiment evaluating carcass characteristics. Physical castrates, IC males, and entire males were assigned to 1 of 4 diet programs with increasing lysine in a step-down lysine inclusion program that culminated with the following concentrations in the late finishing diet: physical castrate with low lysine (0.7%), IC with low lysine (0.7%), IC with low/medium lysine (0.8%), IC with medium/high lysine (0.9%), IC with high lysine (1.0%), and entire with high lysine (1.0%). Bellies were injected with a cure solution to a target of 110% of original green weight, and weighed again to determine brine uptake. Hams were injected with same cure solution to a target of 130% of green weight. Cure solution was formulated for a finished product inclusion of 1.5% salt, 0.34% phosphate, 0.05% sodium erythorbate, 0.11% sugar, and 0.014% sodium nitrate. Physical castrates had thicker (3.77 cm) bellies (P<0.05) than all treatment groups, except IC males fed low/medium lysine (3.73 cm). Entire males (2.85 cm) had the thinnest (P<0.05) bellies of all treatment groups. There were no differences (P>0.05) in percentage brine uptake for cured bellies among IC males regardless of dietary lysine (range 9.93 to 10.67%). Cooked yield of cured bellies was not different (P>0.05) among physical castrates or IC males regardless of lysine inclusion. Cooked yield of cured bellies from entire males (95.12%) was less (P<0.05) than cooked yield for any other treatment group. Pumped weight differences of cured hams among treatment groups were similar to green weight differences, and there were no differences (P>0.05) among any treatment groups for pump uptake percentage. There were also no differences in cook loss percentages among any treatment group. Therefore, differences in cooked yield are a reflection of initial green weight. There were no differences (P>0.05) for protein fat-free values among any treatment groups. Therefore, it can be concluded, in this population of pigs, there were no differences in further processed product characteristics among physical castrates and IC males.

Characterization of loin shape from Duroc and Duroc composite finishing gilts.

Gilts (n=45) were used in this study to characterize the effect of genotype on loin characteristics and quality over the length of the loin. Three diverse genotypes included a high quality Duroc line (A), a Duroc based composite line selected for lean growth (B), and an F1 cross of the two (C). After harvest, bone-in loins were removed from the carcass and cut perpendicular to the backbone at the 5th/6th rib, 7th/8th rib, 10th/11th rib, last rib, midlumbar, and the loin/sirloin juncture. Quality measurements were obtained at the 5th/6th rib, 10th/11th rib, and the loin/sirloin juncture. Digital images were taken of each surface (n=6) and analyzed for the determination of loin muscle area (LMA), muscle width, muscle depth (at three locations across the loin face), and fat depth. The average loin depth was calculated and used to calculate the loin depth:width ratio as an indication of loin shape or conformation. Loins from line A had the lowest (P<0.05) subjective color score, had the highest (P<0.05) amount of marbling, and were the firmest (P<0.05) of all three lines. There were also differences (P<0.05) between genetic lines for LMA, width, all three depths, fat depth, and depth:depth ratios. The most posterior portions of the loin had the largest (P<0.05) LMA, loin width, fat depth, and muscle depth 1. However, the more anterior portions of the loin had greater (P<0.01) values for the depth:width ratio and muscle depth:depth ratios.

The effects of high pressure processing on pork quality, palatability, and further processed products.

The objective was to evaluate high pressure processing (HPP) on postmortem metabolism and pork quality. Six pigs were randomly selected immediately after slaughter. After splitting, one side was randomly designated for HPP of 215 MPa for 15 s with water temperature at 33 °C and the other side (non-pressure treated) served as the control. Chilled sides were fabricated into loins, boneless picnic, boneless Boston butt, and ham. Samples were cut from the loin, inside portion of the ham and cushion (M. triceps brachii). Pork quality, lipid oxidation, connective tissue solubility, protein functionality, sensory analysis, and processed characteristics of restructured hams were evaluated. HPP partially inhibits postmortem metabolism, indicated by lower muscle lactate levels and higher ultimate pH values. Cook and drip loss were both reduced in HPP treated muscles compared to controls. HPP treated sides were more tender than controls. Collagen content was not different between HPP and control groups.

Detection of Mycobacterium avium subspecies paratuberculosis: comparing fecal culture versus serum enzyme-linked immunosorbent assay and direct fecal polymerase chain reaction.

Mycobacterium avium ssp. paratuberculosis (MAP) is the etiologic agent of Johne's disease in cattle. The disease causes diarrhea, reduced milk production, poor reproductivity, emaciation, and eventually death. Culture on Herrold's egg yolk agar is considered to be the definitive test for diagnosis of Johne's in cattle. This method has moderate sensitivity (30 to 50%) and is 100% specific; however, it can take up to 16 wk due to the slow growth of MAP. Currently, serum ELISA is used to screen herds for Johne's disease, but positive tests must be confirmed culturally or by PCR. The current research sought to evaluate an in-house direct fecal PCR procedure and directly compare it to ELISA using culture as the gold standard. Serum and fecal samples were collected from cows (n = 250) with unknown Johne's status. Fecal samples were processed for culture on Herrold's egg yolk agar and direct PCR. Serum samples were tested using the Parachek serum ELISA. Overall, 67/250 [26.8%, 95% confidence interval (CI) 21.4 to 32.8] animals were culturally confirmed to be shedding MAP. The PCR and ELISA detected 74/250 (29.6%, 95% CI 24 to 35.7) and 25/250 (10%, 95% CI 6.6 to 14.4), respectively. Culture and PCR were able to detect more positive animals than ELISA. Overall, direct fecal PCR was 70.2% sensitive and 85.3% specific when using culture as the gold standard. The ELISA method was 31.3% sensitive and 97.8% specific. When culture reported <10 cfu, the sensitivity and specificity of PCR and ELISA were 57.1 and 85.3%, and 4.8 and 97.8%, respectively. When culture reported 10 to <40 cfu, the sensitivity of PCR and ELISA were 75 and 50%, respectively. When culture reported > or =40 cfu, the sensitivity of PCR and ELISA were 100 and 88.2%, respectively. Specificity could not be calculated at these levels because there were no negative samples. The direct PCR outperformed the ELISA in detecting animals potentially infected with MAP and was not significantly different when compared with culture. The direct fecal PCR method described here provides faster results than traditional culture and is more sensitive than ELISA at detecting animals suspected of Johne's disease. These data support the use of PCR as an alternative method for screening herds for prevalence and diagnosis of Johne's disease.

17beta-estradiol pretreatment reduces CA1 sector cell death and the spontaneous hyperthermia that follows forebrain ischemia in the gerbil.

Pretreatment with 17beta-estradiol attenuates ischemia-induced hippocampal cornu ammonis 1 (CA1) neuronal death. We assessed whether this is mediated through prevention of hyperthermia that normally follows ischemia in gerbils. Male gerbils were given sustained-released 17beta-estradiol pellets or sham operation. Later, a guide cannula was implanted for brain temperature measurement and some were implanted with core temperature telemetry probes. Gerbils were subjected to either 5 min bilateral carotid artery occlusion or sham procedures 2 weeks after pellet surgery. Brain temperature was normothermic during surgery in all cases. In experiment 1, only core temperature was measured afterward in untreated and estrogen-treated gerbils. In experiment 2, postischemic core temperature was measured in untreated and two estrogen-treated ischemic groups, one of which had their postischemic temperature increased, via infrared lamp, to mimic the untreated group. Habituation was assessed on days 5 and 6. Hyperthermia, like that which occurs spontaneously, was forced on untreated and estrogen-treated ischemic animals in the third experiment, where brain temperature was measured. CA1 cell counts were assessed after a 7-day survival. A fourth experiment measured brain and core temperature simultaneously in normal gerbils during heating with an infrared lamp. Estrogen did not affect core temperature of non-ischemic gerbils whereas spontaneous postischemic hyperthermia was blocked. Estrogen reduced cell death and provided behavioral protection when gerbils regulated their own core temperature, but not when core hyperthermia was enforced. Conversely, estrogen reduced cell death in gerbils that had their brain temperature elevated. Experiment 4 showed that the brain becomes overheated (by approximately 1 degree C) when core temperature is elevated. Accordingly, estrogen likely failed to reduce CA1 injury in experiment 2, when core hyperthermia was enforced, because of overheating the brain. In conclusion, estrogen reduces CA1 cell death by mechanisms other than preventing hyperthermia. Our results also suggest that future studies regulate brain instead of body temperature.