Role of oviductal pars recta extract on interspecific fertilization between anurans

During their journey through the oviductal pars recta, the vitelline envelope (VE) of Bufo arenarum oocytes encounter structural alterations that make them sensitive to attack by sperm lysin and thus to penetration by sperm cells. The role of pars recta (PR) on the specificity of fertilization between amphibians was analyzed by conditioning Bufo arenarum oocytes with either homologous PR extract (PRE) or Leptodactylus chaquencis PRE. The oocytes were thereafter exposed to sperm lysin preparations from both species. Lysis of the VE only took place when the oocytes were exposed to the homologous PRE. The pattern of protein composition of PRE of these species was strikingly different as shown by Coomassie blue staining of SDS-PAGE. Moreover, antibodies against PR fluid (PRF) of Bufo arenarum produced seven bands of immunoprecipitation in electrophoresed homologous PRE and only one faint band in Leptodactylus chaquencis PRE. Here we show that: (i) the biological activity of PR from Bufo arenarum and Leptodactylus chaquencis over the VE of Bufo arenarum oocytes is species-specific; (ii) this specificity seems to be based in differences in protein structure, which was indicated by the fact that proteins from PRE of Leptodactylus chaquencis and Bufo arenarum were antigenically distinct; (iii) the specificity was solely related to PR activity and not to sperm lysin activity since sperm lysin preparations from both species showed comparable activity.     

Elevated Expression of the cdc25A Protein Phosphatase in Colon Cancer

The nuclear protein phosphatase cdc25A has been postulated to be a protooncogene. The total nuclear phosphotyrosyl protein phosphatase (PTP) activity and the expression of cdc25A were compared in normal and cancerous colon epithelial tissue. Nuclei derived from normal mucosal epithelium and tumors were analyzed for phosphotyrosyl protein phosphatase activity using the malachite green assay and a synthetic phosphotyrosyl peptide based on the sequence of cdc2, a known cdc25A phosphotyrosyl protein substrate. Tumorigenesis resulted in elevated nuclear PTP activity (343.0 ± 37.0% of normal epithelial PTP activity) in 52% (29 of 56) of colon tumors. In all cases elevated nuclear PTP activity correlated with an increase in the expression of cdc25A. The changes in PTP activity observed were not due to any increase in the rate of growth of the colonic mucosa as no corresponding changes occurred with PTP activity under conditions of rapid mucosal growth.     

Glaucolides from Vernonia fulta

Four sesquiterpene lactones were isolated from the aerial parts of Vernonia fulta. Spectral characterization showed that three were new and one was known (i.e. glaucolide-B). The biogenetic relationship among these sesquiterpene lactones is discussed briefly.     

Subtypes of Ataques de Nervios: The Influence of Coexisting Psychiatric Diagnosis

The current study assesses the relationship between presenting symptomatology of the self-labeled Hispanic popular diagnosis of ataques de nervios and the specific co-morbid psychiatric diagnoses. Hispanic subjects seeking treatment at an anxiety disorders clinic (n = 156) were assessed with a specially designed self-report instrument for both traditional ataque de nervios and panic symptoms, and with structured or semi-structured psychiatric interviews for Axis-I disorders. This report focuses on 102 subjects with ataque de nervios who also met criteria for panic disorder, other anxiety disorders, or an affective disorder. Distinct ataque symptom patterns correlated with co-existing panic disorder, affective disorders, or other anxiety disorders. Individuals with both ataque and panic disorder reported the most asphyxia, fear of dying, and increased fear during their ataques. People with ataques who also met criteria for affective disorder reported the most anger, screaming, becoming aggressive, and breaking things during ataques. Ataque positive subjects with other anxiety disorders were less salient for both panic-like and emotional-anger symptoms. The findings suggest that (a) ataque de nervios is a popular label referring to several distinct patterns of loss of emotional control, (b) the type of loss of emotional control is influenced by the associated psychiatric disorder, and (c) ataque symptom patterns may be a useful clinical marker for detecting psychiatric disorders. Further study is needed to examine the relationship between ataque de nervios and psychiatric disorders, as well as the relationship to cultural, demographic, environmental, and personality factors.     

Inertial vestibular coding of motion: concepts and evidence

Central processing of inertial sensory information about head attitude and motion in space is crucial for motor control. Vestibular signals are coded relative to a non-inertial system, the head, that is virtually continuously in motion. Evidence for transformation of vestibular signals from head-fixed sensory coordinates to gravity-centered coordinates have been provided by studies of the vestibulo-ocular reflex. The underlying central processing depends on otolith afferent information that needs to be resolved in terms of head translation related inertial forces and head attitude dependent pull of gravity. Theoretical solutions have been suggested, but experimental evidence is still scarce. It appears, along these lines, that gaze control systems are intimately linked to motor control of head attitude and posture.     

Sensitivity facilitation in the insect eye

Summary ERG amplitude facilitation, observed in the eye ofAtta sexdens after light adaptation, was studied as a function of duration and intensity of adaptation, of dark interval between adapting and test stimuli, and of level of steady background illumination. Results show that sensitivity facilitation in this eye cannot be regarded as a minor effect since it covers a 2 log unit range, the same as that obtained for conditions that produce sensitivity reduction. Maximum facilitation occurs with short and intense light adaptation. The time span of the effect is close to 2 min, and its maximum amplitude may be attained up to 20 s after light adaptation. Increase in background illumination gradually erases facilitation. However, the facilitated response is less sensitive to background illumination than the dark adapted response. Long durations of light adaptation cause ERG decrease, or inhibition. A comparison of these two end results of light adaptation suggests that they arise from different processes, perhaps with distinct origins.Supported by a grant from Fundação de Amparo à Pesquisa do Estado de São Paulo, to the senior author (Contract n 71/1141)With a Fellowship from Fundação de Amparo à Pesquisa do Estado de São Paulo (N 74/388)We wish to express our appreciation to Henrique Fix for his editorial assistance, and to Celia Jablonka for laboratory help.     

Pilot plant scale extraction of alginates from Macrocystis pyrifera 3. Precipitation, bleaching and conversion of calcium alginate to alginic acid

Three steps of the alginate production process were studied at pilot plantlevel. The effect of the amount of calcium chloride used during theprecipitation was measured in terms of filtration time of the precipitatedcalcium alginate. Three different proportions of calcium chloride per gramof alginate were tested. The best proportion used was 2.2 parts ofcalcium chloride per one part of alginate, yielding a filtration rate of 97.9L min^-1 on a screen area of 1.32 m². The method ofadding the solutions and the degree of mixing are discussed as other factorsaffecting the precipitation step. The effect of bleaching the calciumalginate with sodium hypochlorite (5%) was studied. Seven proportions,ranging from 0 to 0.77 mL of sodium hypochlorite per gram of sodiumalginate were tested. The effect of hypochlorite was compared foralginates with three different viscosities. Using alginates with mediumviscosity (300–500 mPa s), the best proportion was 0.4 mL hypochloriteper gram of alginate, yielding an alginate of light cream color with 20%less viscosity than the control. Alginates with lower viscosity showed asmaller loss of viscosity. The effect of pH during conversion of calciumalginate to alginic acid was determined using four combinations of pH,ranging from 2.2 to 1.6, in three acid washings. The extent of conversionwas determined by measuring the percent reduction of the alginate viscosity(RV) in 1% solution before and after adding a sequestrant of calcium. When a pH 1.8 or 1.6 was used for each washing, only two washings werenecessary to produce a RV lower than 40% (maximum recommended). The use of pH 2 required three acid washings to produce the same effect. The pH 2.2 did not remove enough calcium, even with three washings,the RV of the resulting sodium alginate being greater that 40%. Theresults of these experiments provide the information that producers needwhen deciding the best parameters to obtain a product with the desiredcharacteristics.     

Microwave-assisted synthesis of thieno[2,3-c]pyridine derivatives as a new series of allosteric enhancers at the adenosine A(1) receptor

The microwave-assisted aromatization method has been used for the synthesis of a series of novel thieno[2,3-c]pyridines. This rapid method produces compounds in good yield within minutes in comparison with conventional heating method. The synthesized molecules have been evaluated as a potential new series of allosteric enhancers acting at the adenosine A(1) receptor. In a functional assay, one compound (3h) showed activity comparable with that of reference compound PD 81,723.     

Comparative analysis of plant finds from Early Roman graves in Ilok (Cuccium) and Sćitarjevo (Andautonia), Croatia--a contribution to understanding burial rites in southern Pannonia

A comparative archaeobotanical analysis of the plant remains from the Early Roman incineration graves in Ilok and S?itarjevo shows the existence of a complex burial ritual, but at the same time enables a better understanding of the agriculture and trade of the 1st/early 2nd century AD in southern Pannonia. Most of the cereals found (Hordeum vulgare, Panicum miliaceum, Triticum monococcum, T. dicoccon, T. aestivum i T. cf. spelta), the legumes (Lens culinaris, Vicia ervilia) and the fruit contributions (Cucumis melo/sativus, Malus/Pyrus sp., the Prunus avium group, P. domestica, Vitis vinifera) were probably grown in the vicinity of the investigated localities, but they might at the same time have been trade goods. Trade was undoubtedly well developed at that period, as shown by the remains of the fig (Ficus carica) and olive (Olea europaea), typically Mediterranean crops, in the finds. All the species of cereals, except millet (Panicum miliaceum) in S?itarjevo, and of bitter vetch (Vicia ervilia) found in the Ilok grave were carbonised and were probably placed on the funeral pyre with the departed. The lentil (Lens culinaris) and the other fruit remains were non-carbonised and mineralised, which means that they were placed in the grave in fresh, dried or cooked form as food for the deceased (belief in an immortal soul), as remains of the funerary feast, or as a sacrifice to the goods.