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The solid phase FTIR and FT-Raman spectra of Irinotecan have been recorded in the regions 400-4000 and 50-4000 cm(-1), respectively. The spectra were interpreted in terms of fundamentals modes, combination and overtone bands. The structure of the molecule was optimized and the structural characteristics were determined by density functional theory (DFT) using B3LYP method with 6-31G(d) as basis set. The vibrational frequencies were calculated for Irinotecan by DFT method and were compared with the experimental frequencies, which yield good agreement between observed and calculated frequencies. The infrared spectrum was also simulated from the calculated intensities. Besides, molecular electrostatic potential (MEP), frontier molecular orbitals (FMO) analysis were investigated using theoretical calculations.

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The FT-IR and FT-Raman spectral studies of the Methotrexate (MTX) were carried out. The equilibrium geometry, various bonding features and harmonic vibrational frequencies of MTX have been investigated with the help of B3LYP density functional theory (DFT) using 6-31G(d) as basis set. Detailed analysis of the vibrational spectra has been made with the aid of theoretically predicted vibrational frequencies. The vibrational analysis confirms the differently acting ring modes, steric repulsion, conjugation and back-donation. The energy and oscillator strength calculated by Time-Dependent Density Functional Theory (TD-DFT) results complement with the experimental findings. The calculated HOMO and LUMO energies show that charge transfer occur within the molecule. Good correlations between the experimental (1)H and (13)C NMR chemical shifts in DMSO solution and calculated GIAO shielding tensors were found.

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In this study, alginate polymers are used to get homogeneous cylindrical or spherical gels. MRI techniques are employed to study homogeneity of these gels. Four different alginates are used and, for each one, five different concentrations for mechanical tests and three different concentrations for release tests are studied. Mechanical tests are performed to get gels' linear viscoelasticity region and then to evaluate their crosslink density in relation to polymer concentration. Afterwards, three model molecules (theophylline, vitamin B(12), and myoglobin) are loaded within gels to study the release kinetics in water from both cylindrical and spherical gels. Diffusion coefficients calculated from these experiments are then used to estimate the polymeric network mesh wideness. This work shows how crosslink density increases with polymer concentration regardless of the alginate type considered. In addition, while vitamin B(12) diffusion coefficient is inversely proportional to crosslink density, myoglobin is too large to diffuse through the polymeric network, whatever the alginate type and polymer concentration. At the same time, theophylline is too small to be sensibly affected by increasing the polymeric network crosslink density. Finally, MRI analysis and vitamin B(12) diffusion coefficient values prove that, structurally speaking, cylinders and spheres are similar and homogeneous.

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Gracilaria cervicornis, Gracilaria blodgettii and Gracilaria crassissima growing along the coasts of Yucatán were investigated for their agar content. The effect of different concentrations of NaOH in the alkali treatment was evaluated. The three species of Gracilaria produced agars, both native and alkali treated, with different properties confirming the heterogeneity of the agar polymers in this genera. G. cervicornis produces agar polymers with an occurrence of methoxylation and sulphation at the C-6 of the beta-D-galactose residues, and with an extra methylation due to the presence of the 4-O-methyl-alpha-L-galactose residue. The presences of these residues is responsible for the extremely poor gelling ability of its agarocolloids, whose commercial value seems to be quite low. Agar extracts from G. blodgettii showed the typical pattern of unsubstituted agar with a very low degree of methylation on both galactose residues. The discrepancy found between sulphate content and NMR data of agar from this species requires a more detailed structural investigation. G. crassissima produces a good quality agar after sulphate precursor sequences have been removed by alkaline treatment, and it may be considered for exploitation as a source of commercial grade agar. Alkali treatment was effective both in removing alkali-labile sulphate and increasing the gel strength in G. crassissima but not in G. cervicornis and G. blodgettii.

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Six cantaloupe farms and packing plants in South Texas (950 cantaloupe, 140 water, and 45 environmental samples), including the Rio Grande Valley area, and three farms in Colima State, Mexico (300 cantaloupe, 45 water, and 15 environmental samples), were sampled to evaluate cantaloupe contamination with Salmonella and Escherichia coli during production and processing. Samples collected from external surfaces of cantaloupes, water, and the environments of packing sheds on cantaloupe farms were examined for the presence of Salmonella and E. coli. Of a total of 1,735 samples collected, 31 (1.8%) tested positive for Salmonella. Fifteen Salmonella serotypes were isolated from samples collected in Texas, and nine from samples collected in Colima. Two serotypes (Poona and Oranienburg) that have been associated with three large Salmonella outbreaks in the United States and Canada linked to the consumption of contaminated cantaloupe were found in water samples collected at four farms (three from the United States). Susceptibility of Salmonella isolates to 10 antimicrobials was evaluated by disk diffusion. Eighty-eight percent of the isolates from the United States and Mexico were pansusceptible to the antimicrobials tested; eight isolates from the United States demonstrated an intermediate susceptibility to streptomycin and only two isolates were resistant to the same antimicrobial. From Mexico, four isolates showed an intermediate susceptibility to streptomycin and one isolate was resistant to nalidixic acid and streptomycin. Repetitive sequence-based PCR analysis of Salmonella isolates helped to trace potential sources of Salmonella contamination in source water and in subsequent water samples obtained after the filtration systems of U.S. and Mexican cantaloupe farms. No differences could be seen between the levels of Salmonella contamination in melons from both countries.

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A survey of Arcobacter spp. was conducted over a 12-month period in Guadalajara, Mexico. A total of 135 samples (45 lean ground beef samples, 45 lean ground pork samples, and 45 chicken samples, including drumsticks, gizzards, and ground or chopped breast) were collected from local butcheries. The samples were enriched in Johnson-Murano enrichment medium and then streaked onto Johnson-Murano agar plates. Typical colonies were subjected to microscopic and biochemical identification followed by polymerase chain reaction confirmation of the genus Arcobacter. All isolates confirmed to be Arcobacter isolates were then inoculated into Eagle's minimum essential medium to determine their cytotoxicity against Vero cells. Arcobacter spp. were detected in 28.8, 51.1, and 40.0% of beef, pork, and chicken samples, respectively. From these samples, 101 isolates were confirmed to be Arcobacter spp. by polymerase chain reaction. Overall, the species most frequently identified was A. butzleri, followed by A. skirrowii. A. cryaerophilus was isolated only from pork meat. Ninety-five (95%) of the Arcobacter isolates produced a virulence mechanism against Vero cells, and 38 of them induced cell elongation, indicating enterotoxin production. Eighteen isolates produced the formation of vacuoles, and 39 produced both vacuolization and elongation. The vacuolization effect may be related to a vacuolizing toxin. The production of a vacuolizing toxin by Arcobacter spp. has not previously been reported. Results obtained in this study indicate that Arcobacter spp. may show cytotoxic effects other than the recognized enterotoxin production.

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Descriptions of vocal fold lesions related to autoimmune diseases are rare in the literature, and focus mainly on rheumatoid nodules. This is the first report in which autoimmune diseases were promptly suspected by the observation of a unique white transverse submucosal lesion in the vocal fold during clinical examination. This lesion, reported only in autoimmune disease, has been called the bamboo node and its features are different from those of rheumatoid nodules. We report here on two patients who did not have a diagnosis of systemic disease before investigation of their main complaint of hoarseness. At the patients' first visit, vocal fold bamboo nodes were seen in the vocal fold and the otolaryngologist suspected the presence of an autoimmune disease. We requested clinical investigation to clarify our suspicion that there was an underlying systemic disease. After the investigation, both patients were shown to have autoimmune disease, Sjögren's syndrome and systemic lupus erythematous, respectively. This paper emphasizes the important role of the otolaryngologist in the detection of these unique lesions in the vocal folds through the conventional laryngeal methods. These methods consisted of direct observation with a rigid laryngeal endoscope and investigation of the patient's distinctive vibratory pattern by means of laryngeal stroboscopy. The method of treatment we used to obtain the best outcome in terms of voice improvement is also discussed.

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The microaerophilic bacterium Arcobacter has received increasing attention in recent years regarding its presence in food products. There exist a limited number of methods for the detection of this microorganism, with currently available methods being cumbersome to perform, time consuming, and limited in specificity. The objective of this study was to develop a selective enrichment broth to isolate accurately three Arcobacter spp. from concentrated chicken microflora by comparing the efficacy of various selective and growth-promoting additives in order. This newly developed enrichment broth was incorporated into an isolation protocol using a previously developed plating medium, and this new protocol was compared with two existing methods for the isolation of Arcobacter from poultry. Method 1 consisted of enrichment in Ellinghausen-McCullough-Johnson-Harris Polysorbate 80 broth followed by plating on cefoperazone-vancomycin-amphotericin B medium. Method 2 consisted of enrichment in Arcobacter selective broth and plating onto Arcobacter selective medium. Method 3 (the JM method), used a newly developed enrichment broth followed by plating on a previously described JM agar. The JM method isolated Arcobacter strains in 42 out of 50 broiler chicken samples, while methods 1 and 2 detected the organism in only 24 and 15 out of 50 samples, respectively.

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Arcobacter, the newly reclassified Campylobacter species, has been shown to cause diarrhea in both humans and animals. Few studies have been conducted regarding its occurrence in foods because of the lack of effective isolation and identification methods. The purpose of this study was to develop a plating medium that would be selective for the three most commonly found Arcobacter species. The effect of common components used in media intended for the isolation of Campylobacter, Helicobacter, and other gram-negative rods was examined. These components were divided into five distinct groups: (1) basic growth nutrients, (2) reducing and growth-promoting agents, (3) detoxifying agents, (4) antibiotics, and (5) color-enhancing compounds. Components from each of these groups were tested for their ability to recover Arcobacter on a solid medium when incubated aerobically at 30 degrees C for up to 72 h. Growth was evaluated by the ecometric technique, colony size, and differential colony morphology after incubation. After initial evaluations, five formulas showing the best results were selected and tested in detail and compared with brucella agar. A medium containing a basal nutrient mix along with 0.05% thioglycolic acid, 0.05% sodium pyruvate, and 5% sheep's blood (pH 6.9+/-0.2) was found to be the most effective for the growth of A. butzleri, A. cryaerophilus, and A. nitrofigilis. In addition to superior growth characteristics, a deep red color around the colonies also was observed with this formulation.

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Ground pork patties were inoculated separately with 10(9) CFU/g each of three strains of Listeria monocytogenes obtained from the National Animal Disease Center (NADC). Inoculated patties were packaged under vacuum and treated at 414 megapascals (60,000 lb/in2) for up to 60 min by high hydrostatic pressure (HHP). Survivors were determined by surface plating onto modified Oxford agar and trypticase soy agar with yeast extract, as well as by the most probable number method using Listeria enrichment broth. Average D values ranged from 1.89 to 4.17 min, depending on the strain, with the most virulent strain (reported by the NADC) having the highest D value. We tested the usefulness of applying a mild heat treatment at 50 degrees C, simultaneously with HHP, to lower these values. Average D values ranged from 0.37 to 0.63 min, depending on the strain. Thus, a 10-log10 reduction could be achieved even in the most pressure-resistant strain of L. monocytogenes by a 6-min application of heat and HHP. Shelf life studies were also conducted, with spoilage levels reached after 5 days of storage at 4 degrees C for controls versus 28 days for treated samples. Sensory evaluation of uninoculated grilled patties showed that panelists could not distinguish between those treated by heat and HHP and untreated controls (P<0.05). Thus, treatment by HHP in combination with mild heating can be used successfully to produce safer, longer-lasting fresh pork without affecting quality.

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Irradiation of ground beef patties inoculated with the organism Escherichia coli O157:H7 was performed either by gamma rays from a cobalt 60 source or by electron beam generated by a linear accelerator. Patties were packaged in one of the following materials: nylon/polyethylene bags, Saran/polyester/polyethylene bags (PM2), or Saran overwrap with a Styrofoam tray inside. Bags were sealed in air or under vacuum and were irradiated at either 5 or -15 degrees C. Average D10 values (dose required to inactivate 90% of a microbial population) ranged from 0.27 to 0.63 kGy, depending on the conditions. Overall, higher D10 values (P<0.0001) were obtained upon irradiation at -15 degrees C as compared with 5 degrees C. Cells inoculated in samples packaged in PM2 had the highest D10 values, but only if irradiated by electron beam at -15 degrees C (P<0.001). Since PM2 had the lowest oxygen permeability rate and since the temperature was too low for radicals to migrate easily, these conditions may have minimized the effect of oxygen- and water-derived radicals on microbial survival. Irradiation by gamma rays resulted in higher D10 values (P<0.047) than irradiation by electron beam, with the highest values being observed at -15 degrees C. Differences may be attributed to dose rate (1.0 kGy/h for gamma, 17 kGy/min for electron beam) since it is possible that, at low dose rates, microbial enzymes may have more time to repair damage to the cell due to irradiation, resulting in higher D10 values.

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The phenotypic and agarolytic features of an unidentified marine bacteria that was isolated from the southern Pacific coast was investigated. The strain was gram negative, obligately aerobic, and polarly flagellated. On the basis of several phenotypic characters and a phylogenetic analysis of the genes coding for the 16S rRNA, this strain was identified as Pseudoalteromonas antarctica strain N-1. In solid agar, this isolate produced a diffusible agarase that caused agar softening around the colonies. An extracellular agarase was purified by ammonium sulfate precipitation, gel filtration, and ion-exchange chromatography on DEAE-cellulose. The purified protein was determined to be homogeneous on the basis of sodium dodecyl sulfate-polyacrylamide gel electrophoresis, and it had a molecular mass of 33 kDa. The enzyme hydrolyzed the beta-1,4-glycosydic linkages of agar, yielding neoagarotetraose and neoagarohexaose as the main products, and exhibited maximal activity at pH 7. The enzyme was stable at temperatures up to 30 degreesC, and its activity was not affected by salt concentrations up to 0.5 M NaCl.

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Earlier studies conducted in our laboratory showed that heat-shocked Yersinia enterocolitica (45 degrees C for 60 min) are more resistant to a subsequent beat treatment of 55 or 60 degrees C in ground pork than cells not previously heat-shocked. The increased thermotolerance was partly attributed to the production of stress proteins. The present study was performed to determine if the stress proteins produced by heating could also afford protection to the cells to irradiation. As part of the study, the effect of air versus vacuum packaging on survival of Yersinia to irradiation was also examined. Irradiating the inoculated pork at 1.0 kGy was sufficient to completely eliminate this pathogen. The irradiation D value for both heat-shocked and non-heat-shocked cells was statistically the same (0.15 kGy). Neither heat-shocking Yersinia nor packaging under vacuum resulted in increased resistance of this organism to irradiation. In addition, no effect was seen in virulence of the cells after these treatments, when compared with controls.

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Irradiation processing has been researched extensively and is now in use worldwide for many food commodities. Irradiation has been successfully used to reduce pathogenic bacteria, eliminate parasites, decrease postharvest sprouting, and extend the shelf life of fresh perishable foods. Although food irradiation is widely accepted in world food markets, U.S. markets have been slower to accept the idea of irradiated food products. For fruits and vegetables, irradiation is not a cure for shelf life problems; cost and quality problems damage preclude its general use. It appears that the most likely use of irradiation in fruits and vegetables is as an insect control in those commodities for which there is no effective alternative method. For grains such as rice and wheat, irradiation has been used primarily to control insect infestation when insects have been shown to develop resistance to the traditional fumigation methods. Treatment of spices with irradiation doses of 10 kGy has proved to extend shelf life without causing significant changes in sensory or chemical quality. Higher doses that effectively sterilize spices, however, may cause undesirable chemical and sensorial changes. For meat, especially red meat, irradiation is considered a viable alternative in the effort to improve the safety of meat products. With time, the authors believe that economic realities and the technical superiority of irradiation for specific poultry products will lead to public acceptance of the process. Irradiation of seafood products is still being considered for approval by the USFDA, although it is currently used in Asian and European markets, especially for shrimp. It is our belief that scientifically based research in food irradiation and the positive results thereof will also prove economical in the twenty-first century. As we move to a more peaceful world with reduced threat of nuclear holocaust, these valid opinions will prevail and will overshadow the distortions and misinformation generated by the opponents of irradiation.

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The optimal conditions of pressure, time, and processing temperature required to eliminate Listeria monocytogenes Scott A and Salmonella typhimurium ATCC 13311 in fresh pork loin and the effect of these optimal conditions on quality and shelf life were determined. Twenty-five grams of fresh pork loin were inoculated with either of the two organisms and were subjected to pressures between 414 and 827 MPa at either 2 or 25 degrees C for 30 min. The D414MPa(25 degrees C) was determined to be 2.17 min for L. monocytogenes and the D414 MPa (2 degrees C) was determined to be 1.48 min for S. typhimurium. Samples subjected to a 6D process were evaluated by sensory and objective tests as well as for shelf life. These samples were found to be different (P < 0.05) from controls when evaluated after cooking by a triangle test of difference, but only when the pressure was applied at 2 degrees C and not at 25 degrees C. The descriptive analysis test showed that cooked samples treated at 25 degrees C were not different (P > 0.05) from controls in flavor, juiciness, and firmness. Color, peak load, water-holding capacity, and moisture were not found to be different (P > 0.05) between samples treated at 25 degrees C and controls when both were cooked. However, in the raw state, differences were found in the values for color parameters L and b. The level of psychrotrophs was 5.7 log CFU/g for samples treated at 25 degrees C after 33 days of storage at 4 degrees C, as compared with 7.0 log CFU/g for controls. The color and peak load (texture) did not change over the storage period (P > 0.05) in any of the samples. All samples spoiled in 5 days when stored at 25 degrees C.

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We report a rare case of laryngeal myxoma in a 57-year-old Japanese man. Except for a five-year history of gradually progressive hoarseness, he had been in good health. Video-stroboscopic examination revealed a solid mass in the anterior third of the right vocal fold. Phonosurgery performed with a microscope showed that the mass was encapsulated and located between the epithelium and vocal fold ligaments of the right vocal fold. This hard, elastic mass which measured 7 mm in diameter, was diagnosed as a myxoma. Only three cases of myxoma of the larynx have been reported in the English literature, with only one other case involving the vocal fold.

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Irradiation sensitivity of five Salmonella enteritidis isolates inoculated either on the surface or inside of whole shell eggs were determined. The shell eggs were irradiated at doses of 0, 0.5, 1.0, and 1.5 kGy. A minimal dose of 0.5 kGy was sufficient to eliminate all the isolates from the surface of whole eggs; however, the same isolates were more resistant to irradiation when present inside the eggs. The ATCC 13076 isolate was significantly more sensitive to irradiation, with a D value of 0.32 kGy, than the other four isolates from animal origin. Irradiation D values of the latter ranged from 0.39 to 0.41 kGy. Liquid whole eggs were also inoculated (2.4 x 10(6) cells per milliliter) with two S. enteritidis isolates and were heat-treated at 50 C for 0, 20, 40, or 60 min followed by irradiation at 0, 0.25, 0.5, 0.75, or 1.0 kGy. The results indicate that mild heating prior to irradiation was ineffective in reducing the irradiation D values. However, on the basis of the D values obtained, an irradiation dose of 1.5 kGy should be sufficient to reduce Salmonella counts by approximately 4 log10 in both whole shell and liquid eggs. Results also indicate that color and thermal characteristics of the whole or liquid eggs were unaffected by a 1.5-kGy dose of irradiation.

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A modified cefsulodin-irgasan-novobiocin (CIN) medium was developed for the recovery of Arcobacter spp. from meats. Modified CIN was compared to brain heart infusion agar supplemented with 10% bovine blood and cephalothin, vancomycin, and amphotericin B (CVA) as well as brain heart infusion agar supplemented with 10% bovine blood and no antibiotics. The three media were used to recover Arcobacter spp. in a survey of pork-processing plants. Examination of ground pork (149 samples) from one Iowa slaughter facility (Plant #1) revealed that 89 percent of the samples were positive for Arcobacter spp. In a second survey conducted 9 months later involving that same plant and four others, only 5% of the samples from the four plants were found to be positive for Arcobacter spp. Again, 90% of the samples were positive from Plant #1. It was not determined whether the sanitary practices during slaughter or the rearing of pigs on the source farms contributed to the prevalence of Arcobacter spp. in one plant versus another.

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This paper presents optical and chirooptical data on the interaction of the microscopy-staining agent ruthenium red with carboxylated polysaccharides in dilute aqueous solution. The polysaccharides used are both natural (alginate and pectate) and semisynthetic (C6-oxidized cellulose and C6-oxidized amylose). A preliminary discussion of the molecular structure and conformational features which control the interaction is presented.

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Alginates, both commercial and laboratory made, are strongly fluorescent due to small amounts of polyphenolic materials. These contaminants can be detected by fluorescence spectroscopy in concentrations lower than 1 ppm. This technique has been used to measure polyphenols in a wide range of alginates and various procedures for preparation of biotechnological-grade alginates have been evaluated.