General Characterization of Noncommercial Microbial Lipases in Hydrolytic and Synthetic Reactions

Fourteen noncommercial preparations of microbial lipases were investigated with respect to their catalytic activity for hydrolysis and synthesis of ester bonds. Six of the lipases were derived from microorganisms that have not previously been described as lipase producers, and another four were characterized for the first time. The synthetic reactions were carried out in two solvents of different polarities (n-heptane and acetone) using a series of fatty acids and primary and secondary alcohols with different chain lengths. Under the culture conditions employed, Pseudomonas cepacia produced more active enzyme than the other microorganisms. The lipase preparations produced using Ovadendron sulphureo-ochraceum, Monascus mucoroides, Monascus sp., Fusarium oxysporum, Penicillium chrysogenum, Rhodotorula araucariae, Pseudomonas cepacia, Streptomyces halstedii, and Streptomyces sp.were the most efficient catalysts for hydrolysis at lipid-water interfaces. Enzyme preparations from P. cepacia, Streptomyces sp., S. halstedii, and R. araucariae were good biocatalysts for esterification in the polar medium (acetone). When the lipase preparations with the greatest activity for hydrolytic reactions were excluded, regression analysis of the data for the hydrolytic and synthetic activities of the remaining lipase preparations yielded high multiple correlation coefficients for these reactions in both n-heptane and acetone (R = 0.82 and 0.91, respectively).

Vibrissal sense is not the main sensory modality in rat exploratory behavior in the elevated plus-maze

Four groups of male Wistar rats were submitted to acute bilateral removal of mystacial vibrissae at different lengths from the follicle. Each group was divided into two subgroups, tested under high (150 Lux) and low environmental illumination (2 Lux). All the subjects were allowed to freely explore an elevated plus-maze for 5 min. Results indicated that rats tested under low illumination tended to explore the open arms more frequently and longer then rats tested under high illumination. When tested under low illumination, rats in the group that suffered whole vibrissa removal stayed longer in the open arms than those in the other groups but did not differ in the number of entries. The average increase in the length of open arm entries, rather than a decrease in aversion to the open arms, may be due to the need of more time to obtain information about the environment since there is no light and the vibrissae were removed. This effect was not seen with rats tested under high illumination, possibly because vision could be used to obtain relevant information.

Novel microbial lipases: catalytic activity in reactions in organic media

2,000 microbial strains were isolated from soil samples and tested to determine their lipolytic activity by employing screening techniques on solid and in liquid media. Culture broths were initially tested with 1,2-O-dilauryl-rac-glycero-3-glutaric acid-resorufinyl ester, a chromogenic substrate specific for lipases. Fourteen lipase-producing microorganisms were selected and their taxonomic identification was carried out. Hydrolysis of tributyrin or olive oil and the esterification of oleic acid with heptanol were selected to preliminary evaluate the catalytic activity of these lipases. All the selected lipases catalysed this esterification reaction with good yields. Resolution of (R,S)-2-(4-isobutylphenyl) propionic acid, (R,S)-1-phenylethanol, (R,S) 1-phenylethylamine and of (R) or (S) glycidol were performed to evaluate the stereoselectivity of these novel enzymes as biocatalysts in reactions in organic media. Lipases from the fungi Fusarium oxysporum and Ovadendron sulphureo-ochraceum gave the best yields and enantioselectivities in the resolution of racemic ibuprofen and 1-phenylethanol. Several lipases displayed a high stereoselectivity in the resolution of chiral amines by an alcoxycarbonylation reaction.

Cytokine and immunoglobulin concentrations in cervical secretions: reproducibility of the Weck-cel collection instrument and correlates of immune measures

Elucidation of local immune response at the cervix is important for understanding and evaluating STD vaccine approaches currently being proposed. However, no well-validated method exists for the collection of cervical secretions for evaluation of cervical immune response. The purpose of this study was to determine the reproducibility of the Weck-cel sponge used to collect cervical secretions for immunological assessment. Additionally, it was possible to examine correlates of immunity as part of our investigation. Two cervical secretion specimens were collected sequentially from each of 120 women using Weck-cel sponges. Cervical secretions were collected prior to Pap smear sampling to avoid blood contamination. At the laboratory, the duplicate specimens were weighed and tested in replicate wells to determine the concentration of two cytokines (IL-10 and IL-12) and two immunoglobulin isotypes (IgG and IgA). IL-12, total IgG, and total IgA showed a strong correlation between samples from the same woman ranging from 0.78 to 0.84. Kappa coefficients obtained after categorizing assay results ranged from 0.62 to 0.67. Variance components analysis suggested that 69% to 85% of the variance observed was accounted for by between-women variance, with the remaining variability attributed to variation between samples collected from the same woman. IL-10 results were less reproducible than those obtained from the other assays examined, suggesting problems with the assay used to measure this cytokine rather than with the Weck-cel sampling instrument. Various factors were found to significantly correlate with cytokine and immunoglobulin measures at the cervix. Age and reproductive status were associated with all four immune measures; women over 50 years of age and those who were postmenopausal had increased concentrations of IL-10, IL-12, IgG, and IgA. Hemoglobin concentrations were positively correlated with IgG and IL-10 concentrations, but not with IgA or IL-12 concentrations, suggesting local production of IgA and IL-12. The concentration of all immune measures decreased with increasing volume of collection. No significant association was observed between time from collection to freezing of specimens and concentrations of cytokines or immunoglobulins. Overall, our data suggest that measurement of immunological parameters in cervical secretions collected using Weck-cel sponges are reproducible. In addition, various correlates of cytokine and immunoglobulin concentrations were identified.

Phylogenetic analysis of mtDNA lineages in South American mummies

Some studies of mtDNA propose that contemporary Amerindians have descended from four haplotype groups, each defined by specific sets of polymorphisms. One recent study also found evidence of other potential founder haplotypes. We wanted to determine whether the four haplotypes in modern populations were also present in ancient South American aboriginals. We subjected mtDNA from Colombian mummies (470 to 1849 AD) to PCR amplification and restriction endonuclease analysis. The mtDNA D-loop region was surveyed for sequence variation by restriction analysis and a segment of this region was sequenced for each mummy to characterize the haplotypes. Our mummies exhibited three of the four major characteristic haplotypes of Amerindian populations defined by four markers. With sequence data obtained in the ancient samples and published data on contemporary Amerindians it was possible to infer the origin of these six mummies.

A randomized trial of amphotericin B alone or in combination with itraconazole in the treatment of mucocutaneous leishmaniasis

A randomized trial of amphotericin B (AB) alone and in combination with oral itraconazole (IZ) is carried out in two groups of 10 mucocutaneous leishmaniasis patients from Bolivia and Peru. AB+IZ combination is no better than AB monotherapy, as far as efficacy and tolerability are concerned. No antagonism was detected.

Rural campaign to diagnose and treat mucocutaneous leishmaniasis in Bolivia

Mucocutaneous leishmaniasis (MCL) is endemic in the tropical Amazonian lowlands of Bolivia, an area that regularly receives influxes of migratory populations. In these new agricultural development areas, a campaign to diagnose and treat the disease was carried out between 1989 and 1992, in order to provide direct access to MCL treatment in the endemic areas at a standard equivalent to that offered in the urban centres in Bolivia. The campaign led to the creation of decentralized local centres for diagnosis and treatment of the disease. A campaign to inform the population about leishmaniasis was also undertaken and courses were run to educate medical and paramedical personnel. As a result of the campaign, 3285 cases of leishmaniasis were diagnosed, including 2152 cutaneous and 326 mucosal forms. Also, a total of 1888 cases were treated, 1677 of which cutaneous and 211, mucosal.

Electrocardiographic alterations during treatment of mucocutaneous leishmaniasis with meglumine antimoniate and allopurinol

The electrocardiographic (ECG) changes in Bolivian patients with mucocutaneous leishmaniasis, treated with meglumine antimoniate and allopurinol, were evaluated. Electric changes due to the antimonial compound appeared in 45% of the patients, and consisted of repolarization alteration, principally affecting the T wave and the S-T segment. The changes disappeared within 2 months following the end of the antimonial treatment. In patients with associated Chagas disease and leishmaniasis, antimonial therapy did not aggravate the ECG changes characteristic of Chagasic cardiopathy.

Taenia solium ocular cysticercosis: findings in 30 cases

We found the following results in 30 patients with intraocular cysticercosis: (1) a higher incidence in the first two decades of life compared with neurocysticercosis, (2) living cysticerci concomitant with inflammatory reactions, (3) diseases related to immune dysfunction in 17% of the cases, (4) anticysticercus antibodies in 57% of cases, (5) blindness in 81% of patients despite proper surgery, and (6) adult Taenia solium infection in a higher frequency of cases than expected for the Mexican population. We discuss these findings in light of recent and established knowledge regarding this disease.

Functional potential of ectopic marrow autotransplants

Ectopic autotransplants of the marrow tissue, form within 4 weeks, stable nodules which respond to erythropoietic modulation in a manner similar to other parts of the marrow. The findings indicate that these autotransplants are an integral part of the total hemopoietic mass.

Vascular trauma: late sequelae and treatment

58 patients presenting with late manifestations of vascular trauma underwent operative correction at an average of 37.2 months from the date of injury. False aneurysms alone were seen in 23 patients, arteriovenous fistulae in another 35, and both lesions concurrently in 6 patients. Excellent results were achieved in 54 patients, fair results in 4 patients, and only 3 patients required later reoperation despite the chronic nature of these lesions.