Immunopathological evaluation of recombinant mycobacterial antigen Hsp65 expressed in Lactococcus lactis as a novel vaccine candidate.

Bovine tuberculosis (TBB) is a zoonotic disease distributed worldwide and is of great importance for public health and the livestock industry. Several experimental vaccines against this disease have been evaluated in recent years, yielding varying results. An example is the Bacillus Calmette-Guérin (BCG) vaccine, which has been used extensively in humans and tested in cattle showing mixed results related to protection (0-80%) against Mycobacterium bovis. In this study, we used the food-grade bacterium Lactococcus lactis as an expression system for production of mycobacterial protein Hsp65. For this purpose, the construction of a replicable plasmid in strain NZ9000 L. lactis (pVElepr) was conducted, which expressed the Mycobacterium leprae Hsp65 antigen, and was recognized by traded anti-Hsp65 antibodies. The strain NZ9000-pVElepr was applied to calves that were negative to tuberculin test and the immune response was monitored. The results showed that immune response was not significantly increased in calves with NZ9000-pVElepr with respect to control groups, and no injury was observed in any lung or lymph of the calves. Finally, this study suggest that the recombinant NZ9000 strain of L. lactis may protect against the development of M. bovis infection, although studies with longer exposure to this pathogen are necessary to conclude the matter.

Semiochemicals released by pecan alleviate physiological suppression in overwintering larvae of Acrobasis nuxvorella (Lepidoptera: Pyralidae).

Acrobasis nuxvorella Neunzig (pecan nut casebearer) is a monophagous herbivore of Carya illinoinensis (Wang.) K. Koch (pecan); both are indigenous to North America, where Carya has evolved for ≈60 million years. We hypothesized that this close association may have resulted in a parallel evolution allowing casebearer to use pecan volatiles to synchronize seasonality. Casebearer overwinters in diapause as a first-instar larva in a hibernaculum attached to a dormant pecan bud. Larval emergence from this structure after diapause or postdiapause quiescence coincides with the onset of pecan bud growth in the spring, and this interaction was the subject of this study. Dormant pecan twigs with hibernacula-infested buds were exposed to a water control or pecan volatiles from 'Western Schley' cultivar, and monitored to observe larval response by using a microcalorimeter. Initial testing showed that metabolic heat produced by overwintering larvae remained low and unchanged when exposed to water vapor and significantly increased within a few hours after exposure to volatiles from new pecan foliage. This shows that these larvae in hibernacula are in a physiologically suppressed state of diapause or postdiapause quiescence, from which they detect and respond to these pecan volatiles. Further studies to quantify larval responses showed that 90 and 80% of the larvae became active and emerged from their hibernacula ≈6 d after exposure to Western Schley and 'Wichita' volatiles, respectively. Mixtures of 13 sesquiterpenes from those pecan volatiles were identified to induce physiological activity within larvae after hours of exposure, followed some days later by larval emergence from hibernacula. Host volatiles, to our knowledge, have not previously been reported to induce early instar larvae in hibernacula to rouse from a state of physiological arrest to resume normal growth and development. This also has potential for use in pest management.

Mexican Queso Chihuahua: functional properties of aging cheese.

Queso Chihuahua, a semi-hard cheese manufactured from raw milk (RM) in northern Mexico, is being replaced by pasteurized milk (PM) versions because of food safety concerns and the desire for longer shelf life. In this study, the functional traits of authentic Mexican Queso Chihuahua made from RM or PM were characterized to identify sources of variation and to determine if pasteurization of the cheese milk resulted in changes to the functional properties. Two brands of RM cheese and 2 brands of PM cheese obtained in 3 seasons of the year from 4 manufacturers in Chihuahua, Mexico, were analyzed after 0, 4, 8, 12, and 16 wk of storage at 4°C. A color measurement spectrophotometer was used to collect color data before and after heating at 232°C for 5 min or 130°C for 75 min. Meltability was measured using the Schreiber Melt Test on samples heated to 232°C for 5 min. Sliceability (the force required to cut through a sample) was measured using a texture analyzer fitted with a wire cutter attachment. Proteolysis was tracked using sodium dodecyl sulfate-PAGE. Compared with PM cheeses, RM cheeses showed less browning upon heating, melted more at 232°C, and initially required a greater cutting force. With aging, cheeses increased in meltability, decreased in whiteness when measured before heating, and required less cutting force to slice. Seasonal variations in the cheesemilk had minimal or no effect on the functional properties. The differences in the functional properties can be attributed, in part, to the mixed microflora present in the RM cheeses compared with the more homogeneous microflora added during the manufacture of PM cheeses. The degree of proteolysis and subsequent integrity of the cheese matrix contribute to melt, slice, and color properties of the RM and PM cheeses. Understanding the functional properties of the authentic RM cheeses will help researchers and cheesemakers develop pasteurized versions that maintain the traditional traits desired in the cheeses.

Improving antioxidant capacity of fresh-cut mangoes treated with UV-C.

The effect of UV-C irradiation time on total phenol, flavonoids, beta-carotene, ascorbic acid contents, and antioxidant capacity (ORAC, DPPH(*)) of fresh-cut "Tommy Atkins" mango stored for 15 d at 5 degrees C was investigated. Fresh-cut mango was irradiated for 0, 1, 3, 5, and 10 min prior to storage at 5 degrees C. UV-C irradiation for 10 min induced a hypersensitive defense response resulting in the phenols and flavonoids accumulation which was positively correlated with ORAC and DPPH(*) values. However, beta-carotene and ascorbic acid content of fresh-cut mangos decreased with irradiation time during storage. Antioxidant capacity (ORAC, DPPH(*)) was increased in fresh-cut mangoes treated with UV-C irradiation. In conclusion, UV-C irradiation appears to be a good technique to improve the total antioxidant capacity of fresh-cut mango.

Mexican chihuahua cheese: sensory profiles of young cheese.

Sensory profiles of fresh semihard Chihuahua cheese produced in the northern Mexican state of Chihuahua were developed to characterize the flavors and textures of this traditionally made Hispanic-style cheese. Multiple allotments of Chihuahua cheese, 9 brands made with raw milk (RM) and 5 brands made with pasteurized milk (PM), were obtained within 3 d of manufacture from 12 different cheese plants throughout Chihuahua, México. Cheeses were shipped overnight to Wyndmoor, Pennsylvania, and flavor analyses were conducted within 14 to 18 d after manufacture. Four brands (2 RM and 2 PM cheeses) were then selected and multiple allotments were shipped at 3 distinct seasons over a 1-yr period for evaluation of flavor and texture. Microbial analysis was conducted prior to testing to ensure product safety. Descriptive analyses of cheese flavors and textures were conducted with panelists trained to use a universal or product-specific Spectrum intensity scale, respectively. Sensory profiles of cheeses varied among the different manufacturers. The most prominent flavor attributes were salty, sour, diacetyl, cooked, whey, bitter, and milk-fat. The RM cheeses had more intense sour, bitter, and prickle scores than the PM cheeses. Many cheese texture attributes were similar, but RM cheeses were perceived as softer than PM cheeses. As the demand for Hispanic-style cheeses increases, defining and understanding the sensory attributes of traditionally made Mexican cheeses provides guidance to cheese manufacturers as new ways are explored to improve the production and shelf life of the cheeses.

Effect of infiltrated polyamines on polygalacturonase activity and chilling injury responses in zucchini squash (Cucurbita pepo L.).

The effect of exogenous polyamines on electrolyte leakage, chilling index, polygalacturonase activity (PG), ethylene production, and firmness in zucchini squash fruits stored for 12 days at 2 degrees C or 10 degrees C, 85-90% RH was evaluated. Fruits were infiltrated with putrescine (PUT) spermidine (SPD) and spermine (SPM) at 0.1, 0.25, 0.5, 2.0, and 4.0 mM. All polyamines exerted a protective effect on cell and organelle membranes. The most effective was SPD, which reduced electrolyte leakage between 62% and 82%, compared to control fruits stored at 2 degrees C. At 10 degrees C they did not exhibit chilling injury (CI) symptoms, while at 2 degrees C SPM (0.5 mM) and SPD (0.5 mM) diminished them 92% and 100%, respectively; which extended storage life for 8-10 days at 2 degrees C. High concentrations of polyamines (>2.0 mM) caused the appearance of CI symptoms. PG activity diminished proportionally to the concentration of polyamine except for the concentration at 4.0 mM. No significant changes were observed in ethylene production.

Polyphenol oxidase activity, color changes, and dehydration in table grape rachis during development and storage as affected by n-(2-chloro-4-pyridyl)-n-phenylurea.

Flame Seedless grapes were sprayed with N-(2-chloro-4-pyridyl)-N-phenylurea (CPPU) at 0, 2.5, and 5.0 ppm to develop rachis resistant to browning and dehydration. Rachis polyphenol oxidase (PPO) activity was determined during cluster development. Cluster components were weighed at commercial (CM), and physiological maturity (PM). PPO activity, rachis color changes (L and a), and cluster weight loss were evaluated at 0 degrees C for 8, 16, 32, and 56 days. CPPU-treated rachis had a decrease of 36% in PPO activity and a week delay in peak activity. At PM, dry weight of CPPU-treated rachis increased by 3 g. Postharvest rachis PPO activity declined with CPPU application, and color changes followed the same pattern for CM and PM. After 32 days of storage, L and a in lateral branches were significantly superior in CPPU treatments. Weight losses below 2.1% were significantly lowest in CPPU-treated clusters for 16 days of storage regardless of cluster maturity.

[Clinical, structural and functional studies of HbG Philadelphia detected in a Moroccan newborn]. / Etude clinique, structurale et fonctionnelle d'une Hb G Philadelphia dépistée chez un nouveau-né d'origine marocaine.

Hb G Philadelphia (alpha68 Asn leads to Lys) is widely distributed in black people but is uncommon in North-Africa. Only one case has been previously described in an Arab immigrant. The latter and our propositus originated from North-East morocco. Hb G alpha Philadelphia is stable. The abnormal hemoglobin represented 28% of total hemoglobin in the hemolysate of the propositus, a 7 month old child. At birth, 4 fractions were detected on electrophoresis: Hb A, Hb F, Hb G Philadelphia, which migrated like Hb S, and a mutant alpha2Ggamma2. The oxygen affinity of Hb G Philadelphia was slightly elevated. Cooperativity and Bohr effect were normal. The abnormal hemoglobin was also detected in the father of the propositus in the heterozygote state: its clinical and hematological data were normal. No evidence of thalassemia trait was found in the family. The percentage of abnormal hemoglobin obtained in the propositus and his father is in accordance with the presence of two loci for the alpha chain on the homologous chromosome.

[Clinics and genetics of Glanzmann's thrombasthenia (author's translation)]. / Clinique et génétique dans la thrombasthénie de Glanzmann

Glanzmann's thrombasthenia begins in infancy. The most important clinical signs are cutaneous and mucous hemorraghes (purpura, epistaxis, bleeding gums, menorraghia after puberty). The disease proceedes by alternate periods of activity and remission, the frequency and severity of which decrease with age. Death occurred during any of the attachs. Our 10 cases (7 girls, 3 boys) were in 5 "Manouche" gypsies sibships, interrelated by consanguineous marriages. Genetic studies demonstrated that the disease was inherited in the autosomal recessive pattern. The detection of heterozygotes is now possible with an antibody which appeared in a thrombasthenic patient. This antibody agglutinated the normal platelets, but not the ones of thrombasthenic patients. In heterozygotes the agglutinating effects is intermediate between the homozygote and normal.