Electromyographic study of the temporal, masseter and suprahyoid muscles in the mandibular rest position

The temporal muscles (anterior position), and the masseter and suprahyoid muscles were studied electromyographically in 15 subjects with ages ranging from 18 to 35 years, showing normal occlusion (Class I of angle), complete dentition and no dysfunction of the stomatognathic system. The volunteers sat comfortably in a chair, keeping the Frankfurt plane parallel to the boor; the muscles were analysed in the mandibular resting position through a number of stages: with minimum exteroceptive stimuli, relaxation with soft music, abolition of the intrabuccal negative pressure through a plastic tube, stress provoked by an electronic game, disocclusion of posterior teeth using the occlusal splint and finally withdrawal of this device. The electromyographic results were analysed statistically. The samples, were analysed for all of the frequencies of motor units, in a 1-min period. It was found that there were statistically significant difference between the relaxation stages as compared with the withdrawal of negative intraoral pressure and mainly with the stress phase, being this only on the suprahyoid muscles, with 5% significance.

Immunodiagnosis of swine cysticercosis by indirect ELISA employing a heterologous antigen from Taenia crassiceps metacestode

C. Larralde et al. (1990, Arch. Pathol. Lab. Med., 114:926-928) demonstrated that heterologous antigen from the laboratory-adapted murine Taenia crassiceps metacestode may substitute those from Taenia solium in the immunodiagnosis of human cysticercosis by the indirect enzyme-linked immunosorbent assay (IE). ?This antigen is easily obtained at a laboratory level and solves the problem of T. solium cysticerci collection from naturally or experimentally infected swine. In this study an IE employing a heterologous antigen from the T. crassiceps metacestode was evaluated for the immunodiagnosis of swine cysticercosis. Sera from 300 swine free of T. solium cysticerci by post-mortem examination were employed to determine two IE cut- off values: 1) Mean ELISA values + 2 standard deviations (2 sigma cut-off) and 2) - Mean ELISA values + 3 standard deviations (3 sigma cut-off). The specificity of IE was 97% with the 2 sigma cut-off and 100% with the 3 sigma cut-off. When applied to ten sera from swine infected by cysticerci of T. solium by post-mortem examination, the sensitivity of IE was 100% independent of the cut off.

ANATOMICAL STUDY OF THE OPOSSUM (DIDELPHIS-ALBIVENTRIS) EXTRAOCULAR-MUSCLES

The anatomy of the extraocular muscles was studied in 10 adult opossums (Didelphis albiventris) of both sexes. Eight extraocular muscles were identified: 4 rectus muscles, 2 oblique muscles, the levator palpebrae superioris and the retractor ocular bulbi. The rectus muscles originate very close one to another between the orbital surfaces of the presphenoid and palatine bones. These muscles diverge on the way to their insertion which occurs at about 2 mm from the limbus. The levator palpebrae superioris originates with the dorsal rectus and is positioned dorsally in relation to it. The retractor ocular bulbi forms a cone which embraces the optic nerve and is located internally in relation to the rectus muscles. The dorsal oblique originates on the presphenoid bone and after a tendinous trajectory through a trochlea on the medial wall of the orbit, inserts into the ocular bulb. The only muscle arising from the anterior orbital floor is the ventral oblique. The main nerve supply for these muscles is the oculomotor, except for the dorsal oblique which is innervated by the trochlear nerve, and the lateral rectus which is innervated by the abducens nerve. The retractor ocular bulbi receives branches from the inferior division of the oculomotor nerve and some branches from the abducens nerve.

Indirect polarographic and cathodic stripping voltammetric determination of cefaclor as an alkaline degradation product

Cefaclor is not reducible at a mercury electrode, but it can be determined polarographically and by cathodic stripping voltammetry as its initial alkaline degradation product which is obtained in high yield by hydrolysis of cefaclor in Britton-Robinson (B-R) buffer pH 10 at 50 degrees C for 30 min (reduction peak at pH 10, -0.70 V). Differential pulse polarographic calibration graphs are linear up to at least 1 x 10(-4) mol l(-1). Recoveries of 93% of the cefaclor (n = 3) were obtained from urine spiked with 38.6 mu g ml(-1) using this polarographic method with 1 ml urine made up to 10 ml with pH 10 buffer. Using cathodic stripping voltammetry and accumulating at a hanging mercury drop electrode at -0.2 V for 30 s, linear calibration graphs were obtained from 0.35 to 40 mu g ml(-1) cefaclor in B-R buffer pH 10. A relative standard deviation of 4.2% (eta = 5) was obtained, and the limit of detection was calculated to be 2.9 ng ml(-1). Direct determination of cefaclor in human urine (1 ml of urine was made up to 10 ml with pH 10 buffer) spiked to 0.39 mu g ml(-1) was made (recovery 98.6%). (C) 1999 Elsevier B.V. B.V. All rights reserved.

Isolation and sequence determination of peptides in the venom of the spider wasp (Cyphononyx dorsalis) guided by matrix-assisted laser desorption/ionization time of flight (MALDI-TOF) mass spectrometry

Micro-scale (sub-pmol) isolation and sequence determination of three peptides from the venom of the solitary spider wasp Cyphononyx dorsalis is described. We isolated two novel peptides Cd-125 and Cd-146 and a known peptide Thr(6)-bradykinin from only two venom sacs of solitary spider wasp Cyphononyx dorsalis without bioassay-guided fractionation. but instead guided by MALDI-TOF MS. The MALDI-TOF MS analysis of each fraction showed the purity and molecular weight of the components, which led to the isolation of the peptides virtually without loss of sample amount. The sequences of the novel peptides Cd-125 (Asp-Thr-Ala-Arg-Leu-Lys-Trp-His) and Cd-146 (Ser-Glu-Thr-Gly-Asn-Thr-Val-Thr-Val-Lys-Gly-Phe-Ser-Pro-Leu-Arg) were determined by Edman degradation together with mass spectrometry. and finally corroborated by solid-phase synthesis. The known peptide Thr(6)-bradykinin (Arg-Pro-Pro-Gly-Phe-Thr-Pro-Phe-Arg) was identified by comparison with the synthetic authentic specimen. This is the first example for any kinins to be found in Pompilidae wasp venoms. The procedure reported here can be applicable to studies on many other components of solitary wasp venoms with limited sample availability. (C) 2001 Elsevier B.V. Ltd. All rights reserved.

Hardness and compressive strength of indirect composite resins: effects of immersion in distilled water

The aim of this study was to evaluate the effect of ageing in distilled water on the hardness and compressive strength of a direct composite resin Z100, a feldspatic porcelain (Noritake) and three indirect composites (Artglass, Solidex and Targis). For the Vickers hardness tests, five disk-shaped specimens (2 x 4 mm) of each material were prepared according to the manufacturers' instructions. The hardness tests were conducted using a Vickers diamond indentor. Compressive strength measurements were recorded on cylindrical specimens with a diameter of 6 mm and a length of 12 mm. The compression tests were carried out with a constant cross-head speed of 0.5 mm min(-1) on a mechanical test machine. For each material, 10 specimens were tested after 7 days of dry storage at 37 +/- 1 degreesC and 10 specimens were tested after water storage at 37 +/- 1 degreesC for 180 days. Noritake porcelain specimens showed higher hardness values than the composites. Among the composite materials, Z100 promoted the highest VHN values, regardless of the ageing periods. The results showed that Solidex and Z100 had the highest compressive strength values. Ageing in water reduced the hardness for all composites, but had no long-term effect on the compressive strength.

The gradually truncated Levy flight for systems with power-law distributions

Power-law distributions have been observed in various economical and physical systems. Levy flights have infinite variance which discourage a physical approach. We introduce a class of stochastic processes, the gradually truncated Levy flight in which large steps of a Levy flight are gradually eliminated. It has finite variance and the system can be analyzed in a closed form. We applied the present method to explain the distribution of a particular economical index. The present method can be applied to describe time series in a variety of fields, i.e. turbulent flow, anomalous diffusion, polymers, etc. (C) 1999 Elsevier B.V. B.V. All rights reserved.

Indirect determination of chloride and sulfate ions in alcohol fuel by capillary electrophoresis

A capillary zone electrophoresis method using indirect UV detection for the analysis of chloride and sulfate in alcohol fuel samples was developed. The anions were analyzed in less than 3 min using an electrolyte containing 10 mmol 1(-1) chromate and 0.75 mmol 1(-1) hexamethonium bromide (HMB) as electroosmotic flow modifier. Coefficients of variation were better than 0.6% for migration time (n = 10) and between 2.05 and 2.82% for peak area repeatabilities. Analytical curves of peak area versus concentration in the range of 0.065-0.65 mg kg(-1) for chloride and 0.25-4.0 mg kg(-1) for sulfate were linear with coefficients of correlation higher than 0.9996. The limits of detection for sulfate and chloride were 0.033 and 0.041 mg kg(-1), respectively. Recovery values ranged from 85 to 103%. The method was successfully applied for the quantification of sulfate and chloride in five alcohol fuel samples. The concentration of sulfate varied from 0.45 to 3.12 mg kg(-1). Chloride concentrations were below the method's LOD.

Ultrastructure of haemocytes present during flight muscle differentiation of Melipona quadrifasciata anthidioides, Lepidoptera (Hymenoptera, Apidae)

The present work deals with the ultrastructure of the haemocytes present in the dorsal thoracic region of larvae and pre-pupae of Melipona quadrifasciata anthidioides. This is a region of intense muscular differentiation in this phase of life of the insect. Only plasmatocytes, granulocytes, and adiphoaemocytes were found in this area, all showing signs of being intermediate forms.