Control of the growth of Alicyclobacillus acidoterrestris in industrialized orange juice using rosemary essential oil and nisin

The use of rosemary essential oil (RO) and its combination with nisin (RO+N) in preventing the multiplication of Alicyclobacillus acidoterrestris in orange juice was evaluated. The minimum inhibitory and bactericidal concentrations (MIC and MBC) for RO were both 125 μg ml⁻¹ while RO+N displayed a synergistic effect. The use of RO and RO+N at concentrations of 1, 4 and 8× MIC in orange juice for 96 h was evaluated in terms of their sporicidal effectiveness. With regard to the action against A. acidoterrestris spores, RO at 8× MIC was sporostatic, whereas RO+N at 1× MIC was sporicidal. Morphological changes in the structure of the micro-organism after treatment were also observed by microscopy. Furthermore, flow cytometric analysis showed that most cells were damaged or killed after treatment. In general, the antioxidant activity after addition of RO+N decreased with time. The results demonstrate that using the combination of RO and nisin can prevent the A. acidoterrestris growth in orange juice.     

Deletion 2q31.3→2q33.3: gene dosage effect of ribulose 5-phosphate 3-epimerase

In a new case of interstitial del(2q), measurements of ribulose 5-phosphate 3-epimerase activity suggested that the locus for this enzyme might be localized to the subregion 2q32q33.3.     

The amnesic shellfish poison domoic acid enhances neurotoxicity by excitatory amino acids in cultured neurons

Summary A recent episode of human intoxication by cultured mussels containing a rare excitatory amino acid named domoic acid, received particular attention for its neurological implications. The intoxication produced neurological problems, such as headache, confusion, and loss of memory, particularly severe at times. Neuronal damage was found in the hippocampus and amygdala of four patients. We now report that in neuronal cultures the neurotoxicity of a domoic acid-containing mussel extract is the result of domoic acid potentiation of the excitotoxic effect of glutamic acid and aspartic acid present in high amounts in mussel tissue. Moreover, we show that subtoxic concentrations of domoic acid are sufficient to potentiate glutamic acid and aspartic acid neurotoxicity. We present evidence suggesting that the neurotoxic synergism may be due to a reduction of Mg^{+ +} block at the NMDA receptor-associated channel, following activation of NON-NMDA receptors by domoic acid.     

Morphometric investigations of the colon mucosa in chronicTrypanosoma cruzi infected rats

The objective of this investigation was to study the morphometry of the epithelial mucosa in the chronic phase ofT. cruzi infection. Nine young female Wistar rats were inoculated withT. cruzi. Ten months after inoculation the animals were sacrificed and the proximal colon was collected for morphometric measurements of the thickness of the muscle layers, the number of neurons in the myenteric plexus, the crypt cell population (CCP), crypt cell production per crypt (CCPC) and turnover time (TT) of the epithelium. There was no muscle layer hypertrophy but there was significant denervation in the group inoculated withT. cruzi, which also showed hyperplasia of the epithelium. The data suggest that denervation of the myenteric plexus did not induce hypertrophy of the propria muscle layer itself but altered the morphometry of the colonic epithelium inT. crwzi-infected animals, with increased development of CCP and TT. It is possible that this epithelial hyperplasia, as a consequence of a longer crypt cell TT, increased the absorption and secretion activities of the colon, which in turn may participate in the genesis of the enteromegalies observed in the chronic phase of Chagas’ Disease.     

An ESR study of nitrosyl-Aplysia brasiliana myoglobin and nitrosyl annelidae Glossoscolex paulistus erythrocruorin

The nitrosyl derivatives of Annelidae Glossoscolex paulistus hemoglobin (an earth worm erythrocruorin (Ec AGp)) and Aplysia brasiliana myoglobin (Mb Apb) are studied using ESR spectroscopy. These two proteins have a quite similar ESR spectra at 100 K, but a different temperature behaviour. The temperature dependence of the nitrosyl Mb Apb spectrum is in good agreement with the Boltzmann distribution. In the case of nitrosyl-Ec AGp, the results are explained by the existence of two types of spectrum in thermodynamic equilibrium, with delta H = 9.08 kJ/mol, delta S = 47.15 J/mol and T1/2 = 193 K. There is a great similarity of the nitrosyl-Ec AGp spectra with those reported for elephant myoglobin, suggesting the presence of the same heme environment with a glutamine residue in the distal site. The pH dependence of the spectrum of nitrosyl-Mb Apb shows that the affinity of nitrosyl binding is higher at high pH (7.3) than at low pH (4.6). The ESR parameters are the same for these two pH values.     

Increased rate of superoxide ion generation in Fanconi anemia erythrocytes

The rate of generation of superoxide ion, the concentration of Cu, Zn superoxide dismutase and the hematological parameters were measured in red blood cells obtained from Fanconi anemia patients and from healthy individuals. No significative difference in the superoxide dismutase concentration was found, while the rate of generation of the superoxide ion doubled in Fanconi anemia patients. The steady-state concentration of the superoxide ion was calculated from these data and was found to be 2.3 times higher in Fanconi anemia erythrocytes than in controls. The possible consequences with respect to the alterations in FA are discussed.