Formation and Inhibition of Heterocyclic Amines and Polycyclic Aromatic Hydrocarbons in Ground Pork during Marinating.

This study aims to simultaneously extract heterocyclic amines (HAs) and polycyclic aromatic hydrocarbons (PAHs) from ground pork for respective analysis by UPLC-MS/MS and GC-MS/MS, and study the effects of different flavorings and marinating time length on their formation and inhibition. Results showed that both HA and PAH contents followed a time-dependent increase during marinating, with HAs being more susceptible to formation than PAHs. The total HA contents in unmarinated pork and juice was, respectively, 61.58 and 139.26 ng/g, and rose to 2986.46 and 1792.07 ng/g after 24-h marinating, which can be attributed to the elevation of reducing sugar and creatinine contents. The total PAH contents in unmarinated pork and juice were, respectively, 34.56 and 26.84 ng/g, and increased to 55.93 and 44.16 ng/g after 24-h marinating, which can be due to the increment of PAH precursors such as benzaldehyde, 2-cyclohexene-1-one and trans,trans-2,4-decadienal. Incorporation of 0.5% (w/v) cinnamon powder or 0.5% (w/v) green tea powder was effective in inhibiting HA formation with the former showing a more pronounced effect for marinated pork, while the latter was for marinated juice. However, their addition was only effective in inhibiting PAH formation in marinated pork. Principle component analysis revealed the relationship between HA and PAH formation in ground pork and juice during marinating.

Quantification of Gut Microbiota Dysbiosis-Related Organic Acids in Human Urine Using LC-MS/MS.

Urine organic acid contains water-soluble metabolites and/or metabolites­derived from sugars, amino acids, lipids, vitamins, and drugs­which can reveal a human's physiological condition. These urine organic acids­hippuric acid, benzoic acid, phenylacetic acid, phenylpropionic acid, 4-hydroxybenzoic acid, 4-hydroxyphenyl acetic acid, 3-hydroxyphenylpropionic acid, 3,4-dihydroxyphenyl propionic acid, and 3-indoleacetic acid­were the eligible candidates for the dysbiosis of gut microbiota. The aim of this proposal was to develop and to validate a liquid chromatography−tandem mass spectrometry (LC-MS/MS) bioanalysis method for the nine organic acids in human urine. Stable-labeled isotope standard (creatinine-d3) and acetonitrile were added to the urine sample. The supernatant was diluted with deionized water and injected into LC-MS/MS. This method was validated with high selectivity for the urine sample, a low limit of quantification (10−40 ng/mL), good linearity (r > 0.995), high accuracy (85.8−109.7%), and high precision (1.4−13.3%). This method simultaneously analyzed creatinine in urine, which calibrates metabolic rate between different individuals. Validation has been completed for this method; as such, it could possibly be applied to the study of gut microbiota clinically.

Microwave- and Ultrasound-Assisted Extraction of Cucurbitane-Type Triterpenoids from Momordica charantia L. Cultivars and Their Antiproliferative Effect on SAS Human Oral Cancer Cells.

Cucurbitane-type triterpenoids are a major class of bioactive compounds present in bitter melon. In the present study, six different cultivars of bitter melon were extracted by using microwave- or ultrasound-assisted techniques to identify the prominent method that can extract the majority of cucurbitane-type triterpenoids. A UHPLC-MS/MS (ultra-high-performance liquid chromatography tandem mass spectrometry) system was used for the identification and quantification of ten cucurbitane-type triterpenoids. The results suggest that the use of microwave-assisted extraction on cultivars 4 and 5 produced higher amounts of the selected cucurbitane-type triterpenoids. The interpretation of principal component analysis also identified that cultivar 4 is significantly different from the others in which the compounds 3ß,7ß,25-trihydroxycucurbita-5,23(E)-dien-19-al and momordicine I were found in higher quantities. Upon further evaluation, it was also identified that these two triterpenoids can act as antiproliferative agents due to their effects on SAS human oral cancer cell lines.

Analysis and formation of polycyclic aromatic hydrocarbons and cholesterol oxidation products in thin slices of dried pork during processing.

This study aims to determine toxic compounds polycyclic aromatic hydrocarbons (PAHs) and cholesterol oxidation products (COPs) in thin slices of dried pork as affected by different flavorings and roasting temperature treatments through employing a QuEChERS method coupled with gas chromatograph-tandem mass spectrometer (GC-MS/MS) and gas chromatograph-mass spectrometer (GC-MS), respectively. By employing this method, high accuracy and precision was attained for freeze-dried pork hind leg sample. Following addition of 8 different flavorings with roasting temperature at 120, 160, and 200 °C, the levels of total COPs and PAHs in thin slices of dried pork followed a temperature-dependent increase during roasting, which was further confirmed by principle component analysis. High level of soy sauce or sugar inhibited COP formation, while the low-level minimized PAH formation in thin slices of dried pork during roasting. Sugar was more effective in inhibiting COP formation while soy sauce was more efficient in reducing PAH formation.

Integrated multiple multi-photon imaging and Raman spectroscopy for characterizing structure-constituent correlation of tissues.

Histopathological imaging of tissues often requires extensive sample preparation including fixation and staining in order to highlight characteristic alterations associated with diseases. Herein, we report an integrated spectro-microscopy approach based on a combination of multi-modal multi-photon imaging and Raman micro-spectroscopy and demonstrate label-free characterization of the structure-constituent correlation of porcine skin. The multi-modal imaging allows the visualization of dermatological features whereas Raman micro-spectroscopy enables the identification of their 'molecular fingerprints'. By obtaining both structural and molecular-level information of tissue constituents, this integrated approach can offer new insight into the patho-physiological status of tissues.

Necrotizing fasciitis in a medical center in northern Taiwan: emergence of methicillin-resistant Staphylococcus aureus in the community.

BACKGROUND AND PURPOSE: Necrotizing fasciitis (NF) is a rapidly progressive life-threatening infection. It is located in the deep fascia, with secondary necrosis of the subcutaneous tissues requiring urgent surgical and medical therapy. Staphylococcus aureus is, historically, a very uncommon cause of NF, but we have recently noted an increasing number of these infections being caused by community-acquired methicillin-resistant S. aureus (CA-MRSA). METHODS: The medical records of 53 patients diagnosed with NF between January 2001 and December 2005 were reviewed. A standardized instrument was used to abstract information from the medical records of each patient. RESULTS: S. aureus monomicrobial infection accounted for 37.7% (20/53) of the causal organisms noted. Of the 20 strains of S. aureus, 8 were methicillin-sensitive S. aureus and 12 were MRSA. In the 12 patients with MRSA infection, 7 had CA-MRSA. All patients with NF caused by CA-MRSA had no serious coexisting conditions or risk factors. All CA-MRSA isolates were susceptible to ciprofloxacin, trimethoprim-sulfamethoxazole, and vancomycin in vitro. All were cured after surgical intervention and medical treatment. CONCLUSIONS: For patients with severe invasive NF caused by CA-MRSA, glycopeptides may be prescribed as an empirical treatment until susceptibility results. The prognosis of NF caused by CA-MRSA was good after adequate surgical and antimicrobial treatment.

Rapidly progressive necrotizing fasciitis caused by Staphylococcus aureus.

Necrotizing fasciitis (NF) is a rapidly progressive life-threatening infection located in the deep fascia, with secondary necrosis of the subcutaneous tissues. Staphylococcus aureus as a single etiologic agent is rare. The pathogenicity of S. aureus infections is related to various bacterial surface components and extracellular proteins. A 56-year-old man developed fever, hypotension, impaired renal and hepatic functions, disseminated intravascular coagulation, and rapidly progressive NF affecting the 4 extremities due to methicillin-susceptible S. aureus (MSSA). The initial presenting symptoms were general weakness and muscular pain over bilateral thighs and left shoulder, and gradual onset of weakness of the limbs. On the third hospital day, multiple red-purplish discoloration spread across the right lower leg and left forearm. Fasciotomy and debridement was performed on the fifth hospital day, and the diagnosis of NF was confirmed. MSSA was the only pathogen isolated from 4 sets of blood cultures taken on admission and cultures of tissues collected during surgical debridement. The disease progressed rapidly over the 4 extremities despite appropriate antibiotic treatment. He recovered after multiple extensive surgical interventions and 8 weeks of intensive medical care. Early diagnosis, intensive surgical intervention, antibiotic treatment and intensive medical care are crucial for a successful outcome in patients with septic shock and extensive NF caused by S. aureus.