The effect of transglutaminase crosslinking on the rheological characteristics of heated peanut flour dispersions.

Peanut flour (PF) is a high-protein ingredient prepared after the partial extraction of oil from roasted peanut seed. Microbial transglutaminase (TGase) catalyzes protein crosslinking via acyl-transfer reactions, resulting in the modification of functional properties such as viscosity, gelation, solubility, and water holding capacity. This work was conducted to observe changes in rheological properties of PF dispersions in the presence and the absence of TGase and amidated pectin (AP). Dispersions were characterized across a range of conditions, including controlled heating and cooling rates under both large- and small-strain deformations. Gelation occurred at temperatures above 78 degrees C using PF dispersions treated with TGase compared to untreated dispersions devoid of the enzyme (about 68 degrees C). The addition of AP (0.5%) resulted in a general increase in viscoelasticity for all dispersions. AP addition also minimized the shift in gel point temperature caused by TGase polymerization reactions. High-molecular-weight polymers were formed in TGase-treated PF dispersions in both the presence and the absence of AP; however, polymer formation was more rapid in PF dispersions without AP. Ortho-phthaldialdehyde assays indicated about 40% protein coupling in PF dispersions treated with TGase compared to about 20% in those containing both AP and TGase. Collectively, these data suggest potential applications of TGase-treated PF dispersions, both in the presence and the absence of AP, for use in peanut-base food products, including protein bars, shakes, and value-added baked goods.

Pontiac fever due to Legionella micdadei from a whirlpool spa: possible role of bacterial endotoxin.

During January 1998, a cluster of illnesses occurred among hotel guests in Wisconsin. Ill persons had been exposed to the hotel's whirlpool spa and swimming pool. Symptoms included headache, fever, chills, myalgia, shortness of breath, and fatigue. A diagnosis of Pontiac fever was made, based on serologic evidence of acute infection with Legionella micdadei. High concentrations of heterotrophic bacteria were recovered from the spa, despite apparently high disinfectant levels. L. micdadei was isolated from the swimming pool filter and water from the spa after heat enrichment but not from pools and spas at nearby hotels. Water from hotel pools and spas was tested to determine endotoxin levels; water from the spa of the implicated hotel contained the highest concentration of endotoxin (14,400 endotoxin units/mL). Additional studies are needed to determine the role of endotoxin from legionellae or other bacteria in the pathogenesis of Pontiac fever.

Anthelmintic profile of the cyclodepsipeptide PF1022A in in vitro and in vivo models.

A novel cyclodepsipeptide of fungal origin, PF1022A, recently was reported to have anthelmintic activity. To supplement published reports and determine potential utility of PF1022A as a ruminant anthelmintic, the compound was examined in in vitro and in vivo models. Assays used measured motility of Haemonchus contortus (intrinsic drug potency), ATP levels (parasite death), and activity against H. contortus, Ostertagia ostertagi, and Trichostrongylus colubriformis in the jird (spectrum, potency, and efficacy by various routes). The potency of PF1022A in reducing motility is greater than commercial anthelmintics. Examination of ATP levels in PF1022A-paralyzed H. contortus indicates that worms are not killed, suggesting the compound acts as a neurotoxin in nematodes. In the jird, PF1022A has activity orally against each of the parasites studied and at doses comparable to all commercial anthelmintics, except the macrocyclic lactones which are more potent. Unfortunately, for some nematode species, parenteral delivery is ineffective at realistic doses.

Emergence and possible transmission of amantadine-resistant viruses during nursing home outbreaks of influenza A (H3N2).

Outbreaks of influenza A (H3N2, A/Shanghai/11/87-like) occurred in two partially (60% and 79%) vaccinated nursing home populations in January 1988. A retrospective cohort study using chart review was designed to assess the effectiveness of influenza vaccination and amantadine prophylaxis (100 mg per day) in controlling the outbreaks and to determine the amantadine susceptibility of influenza viruses isolated from case-patients. The point estimate of vaccine efficacy in preventing influenza-like illness was -33% (95% confidence interval -115% to 18%). However, 9% of vaccinated case-patients died within 14 days after onset of influenza-like illness compared with 26% of unvaccinated case-patients (relative risk = 0.4, 95% confidence interval 0.1-1.0). There was no significant difference in illness severity among case-patients who became ill before amantadine prophylaxis was started (n = 84) compared with those who became ill while taking amantadine (n = 34). Four virus isolates obtained before amantadine prophylaxis was started demonstrated 52-68% inhibition by 1 microgram/ml of amantadine; by comparison, six isolates (resistant viruses) obtained from residents who became ill while taking amantadine demonstrated 1-18% inhibition. The resistant viruses had four different RNA sequences in the gene coding for the M2 protein transmembrane region. Three resistant viruses with identical RNA sequences were isolated from residents living in contiguous rooms who had onset of signs and symptoms during a 6-day interval. Further studies are needed to determine how frequently and under what circumstances resistant viruses occur when antiviral agents are used to control institutional influenza A outbreaks. Strategies for antiviral agent administration that limit the emergence and transmission of resistant virus strains may be needed.

Accidental self-inoculation with Mycobacterium paratuberculosis bacterin (Johne's bacterin) by veterinarians in Wisconsin.

We surveyed Wisconsin veterinarians to assess the frequency and severity of accidental self- and other human exposure to Mycobacterium paratuberculosis bacterin (Johne's bacterin). Of 199 veterinarians administering the bacterin to cattle, 22 reported one or more exposures, including 19 needle-stick exposures, 8 skin surface exposures, and 2 oral mucosa exposures. The mean incidence of needle sticks was 5.5/100 veterinarians/year of bacterin use or 1/1,000 doses administered. The mean total doses given in the needle-stick exposure group was 276 +/- 318 vs 80 +/- 268 in the group without needle-stick exposure, and the mean number of months administering the bacterin was 21.7 and 16.1, respectively; 63% of needle-stick exposures took place during the injection process. Five adverse reactions were reported, and each resulted from needle-stick exposure. The only systemic reaction followed an exposure to the original bacterin formulation of sonically ruptured M paratuberculosis in Freund incomplete adjuvant. The remaining reactions were to the current formulation of whole killed M paratuberculosis in mineral oil and ranged from a small nodule persisting for 4 to 6 months to painful inflammation of a finger persisting for 24 months. We anticipate an increase in incidence of these minimally debilitating injuries as the use and distribution of the bacterin expands. For hand wounds, we recommend conservative management. Surgical intervention should be considered if a granuloma persists and causes the patient functional difficulty.

Prevention of cecitis in hamsters by certain prostaglandins.

Acute inflammation of the colon (cecitis) was produced in hamsters by daily subcutaneous administration of an antibiotic for 3 days. The following prostaglandins completely prevented the cecitis: 16,16-dimethyl-PGE2, 15(R)-15-methyl-PGE2, and 2-acetyl-2-decarboxy-15(S)-15-methyl-PGF2 alpha. PGF2 beta was less active. The synthesis of 2-acetyl-2-decarboxy-15(S)-methyl-PGF2 alpha is described. Castor oil also prevented the cecitis and peanut oil exerted partial protection. Since these oils contain linoleic acid, a precursor of PGE1, protection may have been due to endogenous formation of that prostaglandin. A partial block of the protective effect of castor oil by treatment with indomethacin supports such mechanism. The tissue level of endogenous prostaglandins seems to exert protection since administration of cyclooxygenase inhibitors, indomethacin and aspirin, markedly increased the incidence of cecitis. Magnesium sulfate given orally and sodium salicylate given subcutaneously reduced the incidence of cecitis only partially. The following agents were inactive: loperamide, an antidiarrheic agent; carbachol, a cholinergic and diarrheogenic agent, atropine, an anticholinergic agent; and acetazolamide, a carbonic anhydrase inhibitor. These results, show that certain prostaglandins, which have been shown earlier to be cytoprotective for the stomach and the small intestine, are cytoprotective for the large intestine as well.