Comparison of sensory texture attributes of broiler breast fillets with different degrees of white striping

The white striping (WS) condition in broiler meat results in increased intramuscular fat, connective tissue, and moisture loss during cooking and negatively affects product appearance and consumer acceptance of skinless chicken meat. The effect of WS on the human perception of cooked meat texture is unknown. The objective of this study was to evaluate the effects of WS on sensory texture attributes of cooked chicken breast fillets (Pectoralis major). Over three separate trial days, a total of 105 breast butterfly fillets were collected from the deboning line of a commercial broiler processing plant. Fillets were classified according to the degree of WS (normal, moderate, severe) and stored at -20°C until use. Fourteen representative fillets from each category were cooked directly from the frozen state to an endpoint temperature of 78°C and evaluated by a 7-member trained panel for five texture attributes: cohesiveness, hardness, juiciness, rate of breakdown, and chewiness. There were no differences (P > 0.05) for juiciness or the rate of breakdown between the fillets based on the degree of WS. Among the three WS groups, however, differences (P < 0.05) in cohesiveness, hardness, and chewiness were observed. For these attributes, the mean intensity scores of fillets with severe WS were consistently highest among the groups. There were no differences (P > 0.05) between the normal and moderate WS fillets. These data suggest that the severe WS condition was perceived to be harder, more cohesive, and chewier than either normal or moderate WS fillets by panelists.

Systematic review with meta-analysis: the diagnostic accuracy of transient elastography for the staging of liver fibrosis in patients with chronic hepatitis B

BACKGROUND

Transient elastography is a non-invasive method for staging liver fibrosis. The meta-analysis using the hierarchical models to evaluate the diagnostic accuracy of transient elastography for the staging of liver fibrosis in patients with chronic hepatitis B was rarely reported.

AIM

A meta-analysis using the hierarchical models was performed to assess transient elastography for diagnosing and stage liver fibrosis in patients with chronic hepatitis B.

METHODS

Electronic databases were searched and studies were identified to assess the diagnostic accuracy of transient elastography in CHB patients for staging fibrosis F ≥ 2, F ≥ 3 and F = 4 with liver biopsy as a reference standard. The hierarchical summary receiver operating characteristic curve and the bivariate models were performed to evaluate the diagnostic accuracy of transient elastography, and meta-regression analyses were performed to explore the heterogeneity. The quality Assessment of Diagnostic Accuracy Studies-2 tool was used to assess the quality of studies.

RESULTS

Twenty-seven studies with a total of 4386 patients were included in the meta-analysis. The summary sensitivity of transient elastography for staging fibrosis F ≥ 2, F ≥ 3 and F = 4 was 0.806 (95% CI, 0.756-0.847), 0.819 (95% CI, 0.748-0.874) and 0.863 (95% CI, 0.818-0.898), respectively, and the summary specificity was 0.824 (95% CI, 0.761-0.873), 0.866 (95% CI, 0.824-0.899) and 0.875 (95% CI, 0.840-0.903), respectively. The corresponding area under the summary receiver operating characteristic curve was 0.88 (95% CI, 0.85-0.91), 0.91 (95% CI, 0.88-0.93) and 0.93 (95% CI, 0.91-0.95), respectively. Meta-regression showed that patient age contributed to heterogeneity.

CONCLUSIONS

Transient elastography performs well to diagnose liver fibrosis in patients with chronic hepatitis B, which may reduce the use of liver biopsy.

Experimental infection of pregnant rabbits with hepatitis E virus demonstrating high mortality and vertical transmission

A high mortality rate of approximately 20% in pregnant women with hepatitis E has been reported in previous studies. However, other studies showed no difference between pregnant and nonpregnant women in the severity of hepatitis E. To determine the effects of HEV infection on pregnancy, we successfully established HEV infection in six pregnant rabbits (PR) and six nonpregnant rabbits (NPR) with a rabbit HEV isolate, taking three PR and one NPR without HEV infection as controls. Tests for HEV RNA by RT-PCR, anti-HEV antibodies by ELISA and HEV antigen via immunohistochemistry and histopathology were carried out. Two of six infected PR miscarried and three of the remaining four PR died which may be attributed to severe liver necrosis caused by HEV infection. Moreover, vertical transmission was found to be associated with the replication of HEV in placenta, indicated by the presence of HEV RNA and antigen in placenta from the infected PR. Our findings strongly suggest that HEV infection could lead to adverse outcomes in pregnancy and vertical transmission, suggesting the necessity for pregnant women at risk of HEV infection to be vaccinated.

Role of p14ARF-HDM2-p53 axis in SOX6-mediated tumor suppression

Sex-determining region Y box 6 (SOX6) has been described as a tumor-suppressor gene in several cancers. Our previous work has suggested that SOX6 upregulated p21^Waf1/Cip1(p21) expression in a p53-dependent manner; however, the underlying mechanism has remained elusive. In this study, we confirmed that SOX6 can suppress cell proliferation in vitro and in vivo by stabilizing p53 protein and subsequently upregulating p21. Co-immunoprecipitation and immunocytofluorescence assays demonstrated that SOX6 can promote formation of the p14ARF-HDM2-p53 ternary complex by promoting translocation of p14ARF (p14 alternate reading frame tumor suppressor) to the nucleoplasm, thereby inhibiting HDM2-mediated p53 nuclear export and degradation. Chromatin immunoprecipitation combined with PCR assay proved that SOX6 can bind to a potential binding site in the regulatory region of the c-Myc gene. Furthermore, we confirmed that SOX6 can downregulate the expression of c-Myc, as well as its direct target gene nucleophosmin 1 (NPM1), and that the SOX6-induced downregulation of NPM1 is linked to translocation of p14ARF to the nucleoplasm. Finally, we showed that the highly conserved high-mobility group (HMG) domain of SOX6 is required for SOX6-mediated p53 stabilization and tumor inhibitory activity. Collectively, these results reveal a new mechanism of SOX6-mediated tumor suppression involving p21 upregulation via the p14ARF-HDM2-p53 axis in an HMG domain-dependent manner.

Relationship between water-holding capacity and protein denaturation in broiler breast meat

The objective of this study was to determine the relationship between water-holding capacity (WHC) attributes and protein denaturation in broiler breast meat. Boneless skinless breast fillets (n = 72) were collected from a commercial processing plant at 2 h postmortem and segregated into low-WHC and high-WHC groups based on muscle pH and color (L*a*b*). At 6 and 24 h postmortem, brine uptake (%), cooking loss (%), and protein solubility (sarcoplasmic and myofibrillar) were measured and protein fractions were analyzed using SDS-PAGE. Drip loss accumulation (%) was measured after storage for 2 and 7 days postmortem. High-WHC fillets exhibited lower L*-lightness values and greater pH values at 2 and 24 h postmortem than low-WHC fillets. High-WHC fillets had greater brine uptake and less cooking loss at both 6 and 24 h postmortem compared to low-WHC fillets. Aging from 6 to 24 h postmortem increased brine uptake in high-WHC fillets, but did not affect cooking loss in either low-WHC or high-WHC fillets. Drip loss accumulation was greater in low-WHC fillets at both 2 and 7 days postmortem. Myofibrillar protein solubility decreased with postmortem time but was not different between low-WHC and high-WHC fillets. Sarcoplasmic protein solubility increased with postmortem time and was greater in high-WHC fillets. SDS-PAGE analysis indicated that low-WHC fillets exhibited more glycogen phosphorylase denaturation than high-WHC fillets as evidenced by a more extensive shift of the protein from the sarcoplasmic to the myofibrillar protein fraction. Correlation analysis revealed that overall protein solubility measurements were not related to WHC attributes but that the degree of glycogen phosphorylase denaturation was significantly correlated (|r| = 0.52 to 0.80) to measures of WHC. Data indicated that WHC differences in broiler breast fillets were not due to differences in myofibrillar protein denaturation and suggested that the denaturation of sarcoplasmic proteins onto myofibrils may influence WHC in breast meat.

Survey of nitrite content in foods from north-east China

This study reports a survey of nitrite in a variety of foods consumed in north-east China and estimates the intake of nitrite for the north-east Chinese consumer. A total of 642 food categories including rice and rice products, flour and flour products, soybean and products, vegetables, fruit, preserved vegetables, cured meat products, dairy products, fish products, salt, and soy sauce were analysed for their content of nitrite. Nitrite content was quite different both between different food categories and within the same food category, ranging from not determined (n.d.) to 19.7 mg kg(-1). A great variation in the content of nitrite was found for all the food products. The average content of nitrite was highest in cured meat products (14.3 mg kg(-1)). Next to that, the nitrite content was high in the order of preserved vegetables (4.1 mg kg(-1)), soybean products (3.5 mg kg(-1)), and dairy products (1.9 mg kg(-1)). The lowest average values of nitrite were detected in soy sauce, rice and rice products, salt and fish products, the contents being 0.1, 0.3, 0.3, and 0.6 mg kg(-1). Calculations on the basis of these results and including dietary surveys show that the average intake of nitrite in north-east China from food was 0.03 mg kg(-1) body weight for an average Chinese person weighing 60 kg, and the data are lower than the established acceptable daily intake (ADI) for nitrite. Cured meat products are normally the major contributor to average nitrite intake of the north-east Chinese population. The second contributor is vegetables.

Effect of postmortem aging on marination performance of broiler breast pectoralis major categorized by color lightness

The objective was to evaluate the effect of postmortem aging on marination performance of early-deboned chicken breast fillets (pectoralis major) with different color lightness. Effects of marination on muscle shear force were also determined. Early-deboned (2 h postmortem) broiler butterfly fillets were visually selected based on their color lightness (pale, normal, and dark) from a commercial plant. The individual butterfly fillets were separated into left and right fillets. One of them was used for 6-h marination treatment and the other for 24-h marination treatment. Samples were marinated in a vacuum tumbler (-0.6 atm, 16 rpm, 20 min) with 20% wt/wt marinade yielding 0.75% NaCl and 0.45% phosphate in the final product. The effect of aging on salt-induced water gain by breast muscle was also measured using the swelling/centrifuging method. Marinade uptake, marinade retention, raw product yield, and cooked product yield were determined after tumbling, following storage for 24 and 48 h after marination and after cooking. Salt-induced water gain was greater (P < 0.05) in nonmarinated fillets at 24 h postmortem compared with 6 h postmortem. Compared with unmarinated fillets, marination enhanced finished product yield significantly (P < 0.05) regardless of postmortem aging and color lightness. Marinade retention and product yield were different (P < 0.05) in fillets categorized by L* (lightness) values. There were no differences (P > 0.05) between 2 postmortem aging times for marinade uptake, overall product yield, cooking loss, final cooked product yield, or meat shear force regardless of initial fillet L* values. However, marinade retention of 6-h samples was significantly better than 24-h samples (P < 0.05). These results demonstrate that with a targeted 15% marinade uptake, postmortem aging of 2-h deboned fillets before marination does not affect marinade uptake and product yield, but significantly affects marinade retention by boneless skinless chicken breast.

Impact of broiler processing scalding and chilling profiles on carcass and breast meat yield

The effect of scalding and chilling procedures was evaluated on carcass and breast meat weight and yield in broilers. On 4 separate weeks (trials), broilers were subjected to feed withdrawal, weighed, and then stunned and bled in 4 sequential batches (n = 16 broilers/batch, 64 broilers/trial). In addition, breast skin was collected before scalding, after scalding, and after defeathering for proximate analysis. Each batch of 16 carcasses was subjected to either hard (60.0°C for 1.5 min) or soft (52.8°C for 3 min) immersion scalding. Following defeathering and evisceration, 8 carcasses/batch were air-chilled (0.5°C, 120 min, 86% RH) and 8 carcasses/batch were immersion water-chilled (water and ice 0.5°C, 40 min). Carcasses were reweighed individually following evisceration and following chilling. Breast meat was removed from the carcass and weighed within 4 h postmortem. There were significant (P < 0.05) differences among the trials for all weights and yields; however, postfeed withdrawal shackle weight and postscald-defeathered eviscerated weights did not differ between the scalding and chilling treatments. During air-chilling all carcasses lost weight, resulting in postchill carcass yield of 73.0% for soft-scalded and 71.3% for hard-scalded carcasses, a difference of 1.7%. During water-chilling all carcasses gained weight, resulting in heavier postchill carcass weights (2,031 g) than for air-chilled carcasses (1,899 g). Postchill carcass yields were correspondingly higher for water-chilled carcasses, 78.2% for soft-scalded and 76.1% for hard-scalded carcasses, a difference of 2.1%. Only in trials 1 and 4 was breast meat yield significantly lower for hard-scalded, air-chilled carcasses (16.1 and 17.5%) than the other treatments. Proximate analysis of skin sampled after scalding or defeathering did not differ significantly in moisture (P = 0.2530) or lipid (P = 0.6412) content compared with skin sampled before scalding. Skin protein content was significantly higher (P < 0.05) for prescald and soft-scalded skin samples than for hard-scalded or soft or hard-scalded skin samples after defeathering. The hard-scalding method used in this experiment did not result in increased skin lipid loss either before or after defeathering.

Sparse representation for classification of dolphin whistles by type

A compressive-sensing approach called Sparse Representation Classifier (SRC) is applied to the classification of bottlenose dolphin whistles by type. The SRC algorithm constructs a dictionary of whistles from the collection of training whistles. In the classification phase, an unknown whistle is represented sparsely by a linear combination of the training whistles and then the call class can be determined with an l1-norm optimization procedure. Experimental studies conducted in this research reveal the advantages and limitations of the proposed method against some existing techniques such as K-Nearest Neighbors and Support Vector Machines in distinguishing different vocalizations.

Hot-boning enhances cook yield of boneless skinless chicken thighs

Three experiments were conducted to evaluate the effects of postmortem deboning time on cook yield of boneless skinless chicken thighs. In experiment 1, chicken thigh meat was deboned at 0.75 (hot-bone), 2, and 24 h postmortem (PM) and trimmed to obtain mainly iliotibialis muscle. Samples were cooked directly from a frozen state. Cook yield of the muscle was significantly influenced by PM deboning time. Hot-boned thighs exhibited a 7% greater cook yield than the samples deboned at 24 h. In experiment 2, boneless skinless chicken thighs were deboned at 0.3, 2, and 24 h PM and cooked directly from a fresh, never-frozen state at 24 h PM. Cook yield of the hot-boned thighs was significantly higher than those of the 2 and 24 h deboned samples, which did not differ from each other. In experiment 3, whole legs (thigh + drumstick) were cut from the carcass backbone at 0.3 (hot-cut), 2, and 24 h PM. Thighs were separated from the legs (drumsticks) at either the same time the whole legs were removed from the carcasses or at 24 h PM. Intact thighs (bone in) were cooked fresh at 24 h PM. Color of fresh thigh muscles, cook yield, and Warner-Bratzler shear force of cooked samples were measured. Cook yield of the thighs cut from the backbone before chilling was significantly higher than those cut from the carcasses at 2 and 24 h PM, which did not differ from each other. The PM time at which intact thighs were separated from the leg (drumstick) did not influence cook yield. These results demonstrate that postmortem deboning time can significantly affect cook yield of boneless skinless chicken thigh products. Deboning chicken thighs after chilling reduces the cook yield. Differences in the cook yield of thighs may also result from the removal of whole chicken legs from the carcass backbone.

Measurement of water-holding capacity in raw and freeze-dried broiler breast meat with visible and near-infrared spectroscopy

The feasibility of using visible/near-infrared spectroscopy (vis/NIR) to segregate broiler breast fillets by water-holding capacity (WHC) was determined. Broiler breast fillets (n = 72) were selected from a commercial deboning line based on visual color assessment. Meat color (L*a*b*), pH (2 and 24 h), drip loss, and salt-induced water uptake were measured. Reflectance measurements were recorded from 400 to 2,500 nm in both raw and freeze-dried breast meat samples. Raw and freeze-dried samples had similar spectra in the visible region (400-750 nm), but the freeze-dried samples exhibited numerous bands in the NIR region (750-2,500 nm) corresponding to muscle proteins and lipids that were not observed in the NIR spectra of the raw samples. Linear discriminate analyses were used to classify fillets as high-WHC or low-WHC according to predicted meat quality characteristics. Using the visible spectra (400-750 nm), fillets could be correctly classified into high-WHC and low-WHC groups based on drip loss and salt-induced water uptake with 88 to 92% accuracy in raw samples and 79 to 86% accuracy in freeze-dried samples. Using the NIR spectra (750-2,500 nm), fillets could be correctly classified into high-WHC and low-WHC groups with 74 to 76% accuracy in raw samples and 85 to 86% accuracy in freeze-dried samples. Thus, freeze-drying enhanced the accuracy of WHC classification using the NIR portion of the spectra. Data from this study demonstrate the potential for utilizing vis/NIR spectroscopy as a method for classifying broiler breast meat according to WHC.

An integrated analysis of SOCS1 down-regulation in HBV infection-related hepatocellular carcinoma

Persistent inflammation together with genetic/epigenetic aberrations is strongly associated with chronic Hepatitis B virus (HBV) infection-related hepatocarcinogenesis. Here, we investigated the alterations of the suppressor of cytokine signalling (SOCS) family genes in HBV-related hepatocellular carcinoma (HCC). A total of 116 patients with HCC were enrolled in this study. The methylation statuses of SOCS1-7 and CISH genes were quantitatively measured and clinicopathological significance of SOCS1 methylation was statistically analysed. The gene copy number variation was assayed by aCGH. Luciferase reporter assay and Western blot were used to detect the involvement of SOCS1 in p53 signalling. We found high frequencies of SOCS1 gene hypermethylation in both tumour (56.03%) and adjacent nontumour tissues (54.31%), but tumour tissues exhibited increased methylation intensity (24.01% vs 13.11%, P < 0.0001), particularly in patients with larger tumour size or cirrhosis background (P < 0.0001). In addition, the frequency and intensity of SOCS1 hypermethylation in tumour tissues were both significantly higher than those in nontumour tissues in male gender patients and in patients ≥45 years old (P = 0.0214 and P < 0.0001, P = 0.0232 and P < 0.0001, respectively). SOCS1 gene deletion was found in 8 of 25 aCGH assayed tumour specimens, which was associated with lower SOCS1 mRNA expression (P = 0.0448). Furthermore, ectopic SOCS1 overexpression could activate the p53 signalling pathway in HCC cell lines. Hypermethylation of SOCS2-7 and CISH genes was seldom found in HCC. Our results suggested that the gene loss and epigenetic silencing of SOCS1 were strongly associated with HBV-related HCC.

Using local binary patterns as features for classification of dolphin calls

An image processing technique called Local Binary Patterns (LBP) has been explored for its ability to generate feature vectors for dolphin vocalization classification. The LBP operator eliminates the need for contour tracing, denoising, and other prior processing. In an experimental study of classifying dolphin whistle types, the performance of the LBP operation was compared with that of the popular contour-based Time-Frequency Parameters (TFP) approach. The preliminary experimental results illustrate that the LBP method produces more consistent classifier accuracy of dolphin whistle calls even when the contour shapes are complex and populated with impulsive clicks and anthropogenic harmonics.

Effects of the frame acquisition rate on the sensitivity of gastro-oesophageal reflux scintigraphy

OBJECTIVE

To compare the sensitivity of gastro-oesophageal reflux (GOR) scintigraphy at 5-s and 60-s frame acquisition rates.

METHODS

GOR scintigraphy of 50 subjects (1 month-20 years old, mean 42 months) were analysed concurrently using 5-s and 60-s acquisition frames. Reflux episodes were graded as low if activity was detected in the distal half of the oesophagus and high if activity was detected in its upper half or in the oral cavity. For comparison purposes, detected GOR in any number of 5-s frames corresponding to one 60-s frame was counted as one episode.

RESULTS

A total of 679 episodes of GOR to the upper oesophagus were counted using a 5-s acquisition technique. Only 183 of such episodes were detected on 60-s acquisition images. To the lower oesophagus, a total of 1749 GOR episodes were detected using a 5-s acquisition technique and only 1045 episodes using 60-s acquisition frames (these also included the high-level GOR on 5-s frames counted as low level on 60-s acquisition frames). 10 patients had high-level GOR episodes that were detected only using a 5-s acquisition technique, leading to a different diagnosis in these patients. No correlation between the number of reflux episodes and the gastric emptying rates was noted.

CONCLUSION

The 5-s frame acquisition technique is more sensitive than the 60-s frame acquisition technique for detecting both high- and low-level GOR.

ADVANCES IN KNOWLEDGE

Brief GOR episodes with a relatively low number of radioactive counts are frequently indistinguishable from intense background activity on 60-s acquisition frames.

Comparison of [123I]MIBG and [131I]MIBG for imaging of neuroblastoma and other neural crest tumors

Meta-iodobenzylguanidine (MIBG), an analog of the adrenergic neurotransmitter norepinephrine, has proven a valuable imaging agent for neuroendocrine and neural crest tumors. Over the past 3 decades, MIBG labeled with [131I] or [123I] has been used widely in imaging of neuroblastoma and pheochromocytoma. Before September 2008 [131I]MIBG was approved as a diagnostic agent only in the US. Due to the excellent physical characteristics of [123I] for imaging with modern scintillation cameras, [123I]MIBG is theoretically more suitable than [131I]MIBG in detecting tumors. In practice, use of [123I]MIBG or [131I]MIBG for diagnostic studies depends on availability and local preference. This review compares [123I]MIBG with [131I]MIBG in imaging of neuroblastoma and other neural crest tumors and also the physical properties of relevant radioisotopes. Dosimetry and scanning protocols of [123I]MIBG and [131I]MIBG, along with their value in depicting disease extent, assessing treatment response and predicting survival are also compared. The performance of post-therapy high-activity [131I]MIBG scans in lesion detectability is also addressed.

[A study on the relationship between HPV infection and the oncogenesis of primary squamous carcinoma of the lung.]

BACKGROUND

To research the relationship between human papillomavirus (HPV) infection and the oncogenesis of primary squamous carcinoma of the lung.

METHODS

50 formalin-fixed paraffin-embedded tissues of squamous cell carcinoma of the lung , 30 samples of areas of squamous epithelium metaplasia near tumors , and 30 samples of normal bronchial mucosa were detected for the presence of HPV DNA by polymerase chain reaction (PCR) .

RESULTS

In these samples , the positive detection rate of HPV DNA was 26%, 36.7% and 10% respectively. Of the detected HPV DNA , HPV16 was of the highest ratio. The positive rate of HPV6/11 and HPV16 in squamous cell carcinoma and squamous epithelium metaplasia had no significant difference by Chi-Square test ( P > 0. 05) .

CONCLUSIONS

These results suggest that HPV infection might play an important role in the oncogenesis of squamous cell carcinomas of the lung , and squamous epithelium metaplasia of the bronchus could be regarded as a precancer lesion. Compared with biotinylated DNA probes and hybridization technique , PCR has a higher sensitivity.