Alternative methodologies for the determination of aldehydes by capillary electrophoresis

This paper describes 2 alternative methodologies for the determination of selected aldehydes (formaldehyde, acetaldehyde, propionaldehyde, acrolein, and benzaldehyde) by capillary electrophoresis (CE), the first approach is based on the formation of aldehyde-bisulfite adducts and employs free solution CE with reversed electroosmotic flow and indirect detection, using 10 mmol/L 3,5-dinitrobenzoic acid (pH 4.5) containing 0.2 mmol/L cetyltrimethylammonium bromide as the electrolyte. This novel methodology showed a fairly good sensitivity to concentration, with detection limits with respect to a single aldehyde on the order of 10-40 mu g/L, a reasonable analysis time (separation was achieved in <8 min), and no need for sample manipulation. A second approach was proposed in which 2,4-dinitrophenylhydrazine derivatives of the aldehydes were detected in a micellar electrolyte medium (20 mmol/L berate buffer containing 50 mmol/L sodium dodecyl sulfate and 15 mmol/L beta-cyclodextrin). This latter methodology included a laborious sample preconcentration step and showed much poorer sensitivity (0.5-2 mg/L detection limit, with respect to a single aldehyde), despite the use of sodium chloride to promote sample stacking. Both methodologies proved adequate to evaluate aldehyde levels in vehicular emissions. Samples from the tailpipe exhaust of a passenger car vehicle without a catalytic converter and operated with an ethanol-based fuel were collected and analyzed; the results showed high levels of formaldehyde and acetaldehyde (0.41-6.1 ppm, v/v). The concentrations estimated by the 2 methodologies, which were not in good agreement, suggest the possibility of striking differences in sample collection efficiency, which was not the concern of this work.

Kinetic aspects of rat (Rattus-norvegicus albinus) submandibular glands lactic-dehydrogenase

Submandibular glands of male rats were homogenized with 33 mM sodium potassium phosphate buffer, pH 6.5, containing 1 mM MgCl2 and 0.1 mM DTT and purified with ammonium sulphate, phosphocellulose chromatography, eluted with KC1 0.5 M, followed by Blue Sepharose CL-6B chromatography, eluted with NADH 0.5 mM. The enzyme kepts stable for 60 days when stored at -15-degrees-C in 33 mM phosphate buffer. In other experiment the enzyme was purified by oxamate-agarose chromatography from a crude extract of submandibular gland and the results obtained were better than by phosphocellulose and Sepharose CL-6B chromatography. The Km values for pyruvate. NADH, lactate and NAD+ were established. Sodium oxamate at 0.1 and 0.9 mM concentrations inhibited the LDH activity by 40 and 85%, respectively (competitive); with sodium oxalate the inhibition was of 30% (uncompetitive) and with 3-acetyl pyridine adenine dinucleotide was 80%.

Immunisation of dogs and guinea pigs against Rhipicephalus sanguineus ticks using gut extract

Tick-bite naive guinea pigs were inoculated three times with Rhipicephalus sanguineus gut or salivary gland extracts and saponin as adjuvant. Dogs were inoculated three times with gut extract only as this fraction induced a more efficient resistance in guinea pigs (lower tick recovery and lower engorged female weights). Freund's adjuvant and saponin were used as adjuvants for the immunisation of dogs. Freund's adjuvant was used to enhance cellular immunity. The highest level of resistance in dogs was induced by the immunisation with gut extract and Freund's adjuvant. Many female ticks from dogs immunised this way engorged fully but died prior to oviposition. Resistant guinea pigs and dogs seemed to trigger different immune mechanisms against R. sanguineus ticks as damage to parasites also differed. A major role for cellular immunity in the resistance of dogs against R. sanguineus ticks is suggested. Resistance mechanisms against R. sanguineus ticks is discussed.

CROSS-REACTIVITY BETWEEN HARD TICK ANTIGENS

1. The present study was carried out to determine the target cells and tissues for anti-tick immunoglobulins using an indirect immunohistochemical technique.2. Sections in triplicate prepared from unfed ticks Rhipicephalus appendiculatus, R. evertsi and Amblyomma variegatum were used to assess the cross-reactivity of serum from guineapigs naturally infested with these tick species or immunized against them.3. The sections showed slight (+) to strong (++++) labelling of several structures in the tick body, e.g. salivary gland, gut lumen and malpighian tubules, depending on the serum used.4. The immune serum resulting from the immunization of guinea pigs with an extract of unfed nymphs of R. appendiculatus ticks showed the most intense cross-reactivity with the sections examined.

Stereological study of acinar growth in the rat parotid gland induced by isoproterenol

The growth of the rat parotid gland induced by daily treatment with isoproterenol (IPR) for 2 weeks was investigated by stereological methods applied to light microscopy. After 7 days of treatment, the glandular mass presented a 286% growth, with the first 3 days being the period of greatest growth. Total acinar volume exhibited a 363% increase during the period from 0 to 7 days, while acinar-cell volume presented a 468% growth from 0 to 5 days of treatment. on the other hand, total acinar-cell number did not increase during the study period. Thus, under the conditions used, IPR-stimulated gland growth wits essentially hypertrophic. However, a significant increase in the number of bipolar and multipolar mitoses was also observed, especially on the third and fifth days of treatment. As no increase in acinar-cell number occurred during growth, the presence of these mitoses suggests that cell death occurred during gland growth. on this basis, bipolar mitoses may occur to replace cells that probably degenerated during treatment, whereas multipolar mitoses may lead to the occurrence of polyploidy. (C) 1997 Elsevier B.V. Ltd.

Cortisol in saliva and plasma of cattle after ACTH administration and milking

Interest in the measurement of salivary cortisol has increased recently because saliva can be easily collected before and after an imposed stress. This study evaluated the relationship between plasma and salivary concentrations of cortisol following ACTH administration in calves ( experiment 1) and machine milking of adult cows ( experiment 2). A catheter was inserted into the jugular vein of all animals 72 h before the beginning of experiments. Blood and saliva samples were collected before and after ACTH administration (0.6 IU/kg BW) in calves or before and after machine milking of cows. Using a cotton swab, each saliva sample was taken immediately following the blood sample. In general, cortisol profiles were similar in plasma and saliva and correlated in both experiments; however, plasma concentrations were significantly higher than salivary concentrations. In addition, the differences between cortisol concentrations measured in saliva and plasma within each experiment varied substantially between animals and samples. Furthermore, in experiment 2, nearly 10% of salivary samples were below limits of detection. The sharp peaks in cortisol after ACTH administration in both the plasma and saliva were reflected adrenal stimulation. In addition, increases in cortisol in response to milking in both the plasma and saliva suggest that salivary sampling is a reliable option when studying cortisol responses to normal physiological events.

Characterization of the cellular component of polymorphous low-grade adenocarcinoma by immunohistochemistry and electron microscopy

In order to characterize the cellular component of the polymorphous low-grade adenocarcinoma (PLGA) of the salivary gland, a morphological and immunohistochemical study was carried out. Thirty cases of PLGA were studied by light microscopy and immunohistochemistry and five cases by transmission electron microscopy (TEM). The expression of cytokeratins (CKs) 7,8,10,13,14,18,19, vimentin and muscle-specific actin (MSA) was investigated through the streptavidin-biotin method. The majority of tumor cells stained for vimentin, CKs 8,18 and 7. CK 14 was positive in most cells of the papillary and trabecular sub-types. Although the expression of CKs 8,18 and 14 varied among the tumors sub-types, a straight relationship between each histologic pattern and the CK expression could not be delineated. MSA was reactive in only three tumors while CKs 10 and 13 were not detected in any tumor studied. The absence of MSA and the expression of CKs 8,18 and 7, in most of the tumor cells, lead to the hypothesis that myoepithelial cells are not the major cellular component of the PLGA. TEM revealed cells exhibiting microvilli and variable amounts of secretory granules, some of them suggesting an excretory activity. The presence of CKs 8, 18 and 7, added to the secretory granules, indicates that PLGA originates from cells located at the acinar-intercalated duct junction. (C) 1999 Elsevier B.V. Ltd. All rights reserved.

Reproductive compatibility and chromosome pairing in the Drosophila buzzatii complex

Fertility (percentage of fertile crosses) and the degree of synapsis in salivary gland chromosomes in isofemale lines of Drosophila buzzatii, D. serido, D. koepferae and D. seriema were analysed. D. buzzatii was completely sterile in intercrosses with strains from the other species except for D. koepferae. The other species intercrossed to a greater or lesser degree, but also differed between crossing directions. Homologous pairing in salivary gland preparations of strains and hybrids conformed with the data on fertility. The lowest degree of synapsis was present in hybrids between D. koepferae and D. buzzatii, D. seriema and D. koepferae and D. koepferae and D. serido. These species also exhibited the lowest degree of reproductive compatibility. Hybrids between D. seriema and D. serido showed an intermediate degree of synapsis (pairing absent in the proximal and distal chromosome ends), as well as fertility greater than that found in the other interspecific crosses. Results of the fertility of crosses involving strains of a single species, compared with data in the literature, indicated that intraspecific divergence occurred in D. serido and D. koepferae.

Cross-reactivity between antigens from Amblyomma cajennense and A-hebraeum (Acari : Ixodidae)

Laboratory animals exposed to feeding ticks develop resistance which is reflected by a decline in tick engorgement weight, egg-laying by adults and reduced egg viability. Serum antibodies from these hosts and their reaction with tick antigens have been detected by different methods, including precipitation techniques, immunofluorescent techniques, ELISA and Western blots. However, little is known about the effects of antibodies on ticks that engorge on resistant hosts, or which tissues of the tick body are possibly immunogenic. Some researchers, using immunohistochemistry, have detected host antibodies in the gut, salivary glands and haemolymph of ticks engorged on resistant animals. The same technique has helped considerably in determining antigenic sites or antibody targets in other arthropods. Consequently, immunohistochemistry techniques were used in this study to detect cross-reactivity between sera raised against Amblyomma cajennense (Fabricius, 1787) with Amblyomma hebraeum (Koch, 1844), and vice versa. The results show the existence of shared antigens between the 2 tick species. In general, our results point more to a 1-way cross-reactivity of A. hebraeum with A. cajennense than a reciprocal cross-reactivity, suggesting that A. hebraeum is more immunogenic than A. cajennense.

Determination of low-aliphatic aldehydes indoors by micellar electrokinetic chromatography using sample dissolution manipulation for signal enhancement

This work describes a novel approach for the analysis of selected aldehydes (formaldehyde, acetaldehyde, propionaldehyde, and acrolein) and acetone in environmental samples using micellar electrokinetic chromatography (MEKC). The method is based on the reaction of carbonyl compounds with 3-methyl-2-benzothiazoline hydrazone (MBTH) that gives an azine intermediate with maximum absorbance at 216 nm. A systematic evaluation of sample dissolution medium was conducted as a means to enhancing sensitivity. In the best condition, samples were dissolved in 0.030 mol.L-1 tetraborate solution. This condition presented enhancement factors in the range of 35-54 for the aldehydes under investigation, computed as the improvement of the concentration limits of detection (LODs) with reference to the sample dissolved in pure water. The running buffer was 0.020 mol.L-1 tetraborate, pH 9.3, containing 0.050 mol-L-1 sodium dodecyly sulfate (SIDS). The overall methodology presented several advantages over established methods for aldehydes. Worthy mentioning that MBTH is available in high purity degree, dispensing laborious reagent purification procedures. A few method validation parameters were determined revealing good migration time repeatability (< 2.5% coefficient of variation, CV) and area repeatability (< 4% CV), excellent linearity (20-120 mug/L, r > 0.995) and adequate sensitivity for environmental applications. The LODs with respect to each single aldehyde were in the range of 0.54-4.0 mug.L-1 and 11 mug.L-1 for acetone. The methodology was applied to the determination of aldehydes indoors. Samples were collected in an impinger flask containing 0.05% MBTH solution, at a flow rate of 0.80 L.min(-1), during 2.5 h, at different times during the day. The most abundant carbonyls in the samples were acetone, followed by formaldehyde and acetaldehyde, with estimate peak concentrations of 452, 5.2 and 2.2 ppbv, respectively.

A Semi-Continuous Analyzer for the Fluorimetric Determination of Atmospheric Formaldehyde

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Localization of Antigenic Sites in Unfed Nymphs of Amblyomma triste Koch 1844 (Acari: Ixodidae) Ticks by Immunohistochemistry

P>The reactivity of sera collected from guinea pigs after three infestations with Amblyomma triste nymphs on histological sections of the same tick species was investigated through immunohistochemistry to identify potential target cells and tissues. Six guinea pigs were infested thrice, at 30 day intervals, with 30 nymphs of A. triste per animal per infestation. Blood samples were collected from the guinea pigs 15 days after each infestation for serum separation; normal serum was obtained before the first infestation as control. Unfed A. triste nymphs' histological sections were submitted to indirect immunohistochemistry technique by using normal or hyperimmune guinea pig serum as primary antibody and a goat IgG-alkaline phosphatase-APase conjugate as secondary antibody. A weak to moderate APase activity was observed in cells of salivary glands, midgut and haemolymph of unfed nymphs incubated with hyperimmune serum.

Pediatric Chronic Sclerosing Sialadenitis: Kuttner Tumor

Chronic sclerosing sialadenitis is an uncommon cause of salivary gland enlargement mainly occurring in the fifth and seventh decade of life. In the Western population, chronic sclerosing sialadenitis has been characterized as an IgG4-related disease. Although rare, this lesion occurs in children. To increase awareness about this entity in the pediatric age group, we report the case of an 11-year-old boy with a hard, 4.0-cm circumscribed mass in the right submandibular gland. Histologically there was marked distortion of the gland architecture by a dense lymphocytic infiltrate and extensive fibrosis with septa that crossed and distorted the gland, leaving atrophic acini and dilated, irregular ducts. The lymphoid infiltrate formed multiple follicles with active germinal centers, numerous plasma cells, and areas with diffuse arrangement. Immunophenotyping showed abundant CD20- and CD3-positive lymphocytes; cytokeratin AE1/AE3 highlighted the distorted architectural pattern; IgG staining showed large numbers of positive cells infiltrating the interstitium and surrounding the atrophic acini and ducts. IgG4 staining revealed a large proportion of positive infiltrating elements. Kuttner tumor belongs to the group of IgG4-related sclerosing diseases. The differential diagnosis includes pleomorphic adenoma and other salivary gland neoplasms. Its recognition in children is important clinically because this entity is amenable to steroid treatment, and additional work up and follow up is warranted to stave off other IgG4-related diseases/complications.

Evidence of zinc deficiency in competitive swimmers

Objective: The aim of this study was to assess the nutritional zinc (Zn) status of elite swimmers during different training periods.Methods: A longitudinal paired study was performed at the University of São Paulo in eight male swimmers 18 to 25 y old who had been swimming competitively at the state and national levels for at least 5 y. The swimmers were evaluated over a total period of 14 wk: before the basic and specific preparatory period (BSPP-baseline), at the end of the basic and specific preparatory period (post-BSPP), and at the end of the polishing period (PP). Levels of Zn were determined in the plasma, erythrocyte, urine, and saliva by atomic absorption spectrophotometry. Anthropometric measurements and a 3-d food record were also evaluated.Results: The median plasma Zn concentration was below the reference value in all training periods (BSPP-baseline 59 mu g/dL, post-BSPP 55.9 mu g/dL, after PP 58.8 mu g/dL, P > 0.05), as were threshold values for erythrocytes (BSPP-baseline 36.5 mu g of Zn/g of hemoglobin, post-BSPP 42 mu g of Zn/g of hemoglobin, after PP 40.7 mu g of Zn/g of hemoglobin, P > 0.05), urinary Zn (BSPP-baseline 280 mu g/24 h, post-BSPP 337 mu g/24 h, after PP 284 mu g/24 h, P > 0.05), and salivary Zn (BSPP-baseline 66.1 mu g/L, post-BSPP 54.1 mu g/L, after PP 79.7 mu g/L, > 0.05). Salivary Zn did not correlate with plasma and erythrocyte Zn levels.Conclusion: The results suggest that the elite swimmers studied presented a possible Zn deficiency and that salivary Zn was not adequate to evaluate the Zn nutritional status. (C) 2012 Elsevier B.V. All rights reserved.