A procedure to prepare cultured cells in suspension for electron probe X-ray microanalysis: application to scanning and transmission electron microscopy

We describe a simple procedure to prepare cultured cells in suspension to analyse elemental content at the cellular level by electron probe X-ray microanalysis. Cells cultured in suspension were deposited onto polycarbonate tissue, culture plate well inserts, centrifuged at low g, washed to remove the extracellular medium, cryofixed and freeze-dried, and analysed in the scanning mode of a scanning electron microscope. We tested the effect of different washing solutions (150 mM ammonium acetate, 300 mM sucrose, and distilled water) on the elemental content of cultured cells in suspension. The results demonstrated that distilled water was the best washing solution to prepare cultured cells. In addition, the low Na content, high K content and high K/Na ratio of the cells indicated that this procedure, based on the centrifugation at low g followed by cryopreparation, constitutes a satisfactory method to prepare cultured cells in suspension. We also investigated the effects of different accelerating voltages on X-ray signal collection. The results showed that moderate accelerating voltages, i.e. 10-11 kV, should be used to analyse whole cells in the scanning mode of the scanning electron microscope. We show that this method of preparation makes it possible to prepare cryosections of the cultured cells, thus permitting analysis of the elemental content at the subcellular level, i.e. nucleus, cytoplasm and mitochondria, using a scanning transmission electron microscope.

Immunotherapy with a mass unit Parietaria judaica extract: a tolerance study with evidence of immunological changes to the major allergen Par j 1

Specific immunotherapy with Parietaria judaica pollen extract has been proven to be effective in the treatment of patients with respiratory allergy induced by this pollen. Nevertheless, there is some controversy about its tolerability. We conducted an open uncontrolled study to evaluate the tolerability of an aluminium adsorbed P. judaica pollen extract whose major allergen (Par j 1) content was known. Changes in immunological parameters to a complete P. judaica extract and to a purified Par j 1 preparation were monitored. Twenty-one patients (12 women, 9 men; mean age 30.2 years) suffering from rhinoconjunctivitis and/or asthma due to Parietaria pollen were enrolled. The maximum dose was established at 10 BU/ml (0.6 microgram Par j 1). Skin and conjunctival reactivity as well as serum levels of specific IgE, IgG, IgG1 and IgG4 were evaluated before therapy (T0), when 1 BU was given (T1), 2 weeks after the maintenance dose was reached (T2) and after the pollen season (T3). Four-hundred and fifteen doses were administered during immunotherapy. Only one systemic reaction (0.24% of doses) and two local reactions were registered. Reactions occurred during the administration of the highest concentrated vial. Before immunotherapy, purified Par j 1 accounted for 94.2% of the cutaneous response elicited by the complete extract. A statistically significant decrease in cutaneous response was detected after 8 weeks of treatment. There were no significant changes in conjunctival reactivity throughout the study. Specific IgG, IgG1 and IgG4 showed a pronounced and significant increase during the study, while specific IgE levels initially decreased and increased after the pollen season. The kinetics of specific antibodies to P. judaica complete extract and purified Par j 1 showed a parallel trend. The present study demonstrates that immunotherapy with P. judaica extract is well tolerated in patients suffering from rhinoconjunctivitis and/or asthma due to Parietaria pollen. This therapy induces specific changes in the immunological response to P. judaica and to purified Par j 1. These changes can be detected at very early stages of therapy.

Capacity for mental imagery and its spontaneous use

The aim of this study was to investigate whether the capacity to form mental images influences the frequency with which subjects use mental images. Two tests measuring capacity for mental imagery were given to 283 undergraduates, a self-assessment and a performance test. Frequency of spontaneous use of mental imagery was also measured. Subjects with high self-assessed ability to form images used mental imagery spontaneously more often than those with low self-assessed imaging ability.

Emotionality of words as related to vividness of imagery and concreteness

We investigated the association of the imagery and concreteness of words on their emotionality. Emotionality was evaluated on the basis of skin conductance. A total of 61 subjects (all university students) rated the vividness of imagery and concreteness of the words in a list of 25 word pairs. Each pair was comprised of one abstract word and one concrete word with a related meaning, e.g., "friendship" and "friend," thereby controlling meaning. The skin-conductance response of each word was measured subsequently from these same subjects. Our results show that both imagery and concreteness were significantly related to emotionality.

Improvement of the friction behaviour of NiTi orthodontic archwires by nitrogen diffusion

The lack of low friction coefficient for the NiTi superelastic archwires makes difficult the optimal use of these materials in orthodontic applications. In this study, the decrease of this friction coefficient has been achieved by means of nitrogen diffusion heat treatments. The titanium nitride coating has been characterised by means of optical and scanning electron microscopy. Transformation temperatures, critical stresses, hardness and friction coefficient have been determined. Besides, the metallic ion release studies showed that the titanium nitride coating prevents biodegradation.

The crystalline pattern of calcium in different topographical regions of the otoconial membrane. An electron probe and spectroscopic diffraction study

Quantitative electron probe microanalysis and electron spectroscopic diffraction analysis was used to determine the gradient of distribution of calcium and its crystalline pattern at different levels (lower gelatinous membrane, upper gelatinous membrane and otoliths) in the otoconial membrane of adult OF1 mice. Our quantitative electron probe microanalytical data, obtained with scanning-transmission electron microscopy, indicated that there was a gradient in calcium concentration which increased from the vestibular surface towards the otoliths. Differences between the three regions of the otoconial membrane were statistically significant in both the utricle and saccule. Our results with electron spectroscopic diffraction revealed an increasing crystalline development from the lower gelatinous membrane towards the otoliths. Our findings with both techniques suggest that the gelatinous membrane is involved in the maturation and crystallization of the otoliths.

A measure of visual imaging capacity: a preliminary study

The capacity to form images is generally measured by means of questionnaires based on self-evaluation, despite the limitations of this approach. Here we describe a new performance-based test, the Vividness of Visual Imagery Test, designed for assessing imaging capacity of adults. There are 21 items, each of which requires the subject first to visualize a certain object, then to choose between a correct and an incorrect description of that object. For 351 university students Cronbach alpha was .58 and validity of the test also requires further work.

Crystallization and preliminary X-ray analysis of FlhD from Escherichia coli

The flhD gene from Escherichia coli codes for one of the transcriptional activators of flagellar genes and is a putative global regulator in the cell. FlhD together with FlhC forms a complex that positively regulates the expression of flagellar genes. However, FlhD is able to change its DNA binding specificity, probably by forming another complex with some unknown factor or by binding to other targets by itself. FlhD is a good model to study the DNA binding specificity by complex formation. The FlhD three-dimensional structure will certainly improve our understanding of this protein, which is the first case of combinatory specificity in prokaryotes. The flhD gene was over-expressed, and the resulting protein was purified to homogeneity. FlhD crystals were obtained from 15-25% PEG 5000, 0.05-0.1 M lithium sulfate, 0.1 M Tris, pH 8.5, or 20-30% PEG 5000, 0.05-0.2 M sodium acetate, and 0.1 M Tris-HCl, pH 8.5, as precipitant solutions, and belong to the space group I4 with unit cell parameters of a = b = 90 A, c = 42.6 A, and alpha = beta = gamma = 90 degrees and contain two molecules per asymmetric unit. A complete native data set has been collected to 2.3-A resolution.

[Role of nasosinusal endoscopic surgery in the treatment of headache and facial pain of rhinogenic origin]

Headaches and facial pain are common complaints. In many cases patients are referred to an otolaryngologist to determine if head pain is sinus related. In the absence of other nasal or sinus symptoms, some rhinogenic headaches can be overlooked or misdiagnosed. A complete history and thorough ENT examination, including nasal endoscopy, with or without coronal CT scans, is the key to the correct diagnosis. Subtle exploratory findings such as minimal inflammatory changes or anatomic abnormalities of the ostiomeatal complex area may cause pressure resulting in facial pain. When medical treatment fails to produce sustained relief, surgery may be considered. Current worldwide thinking firmly supports the endoscopic endonasal approach as a safe and effective form of treatment in patients with nasal and sinus disease. We prospectively assessed 67 patients who underwent FESS for rhinogenic facial pain in the absence of other nasal or sinusal symptoms. The overall success rate was 93%. Only 5.9% of our cases had some minor complications. No major complications occurred.

The captopril renogram: a new tool for diagnosing and predicting obstruction in childhood hydronephrosis

PURPOSE

We evaluated the difference in response patterns of captopril versus standard renography for assessing hydronephrosis due to suspected ureteropelvic and ureterovesical junction obstruction. This technique may identify hydronephrotic kidneys in which normal function is maintained by vasoactive compensatory mechanisms. Sustained obstruction may cause these mechanisms to fail, and expose the kidneys to permanent functional deterioration in the long term.

MATERIAL AND METHODS

We prospectively studied 15 boys and 8 girls with a mean age of 3.5 years with grades III to IV/IV hydronephrosis. Evaluations included renal sonography, standard diuretic and captopril renography, glomerular filtration rate, voiding cystography, serum creatinine, blood pressure, and urinalysis with culture and sensitivity. Obstruction was suspected at the ureteropelvic junction in 19 kidneys and at the ureterovesical junction in 9. We compared differential function values obtained by standard diuretic and captopril renography.

RESULTS

We observed certain patterns in response to captopril renography, including pattern 1--unilateral decrease in hydronephrotic kidney relative function in 5 of 23 cases, 2--bilateral decreased function in 2, 3--bilateral increased function in 4 and 4--no change in function in 12 on standard renography. When half-time was more than 20 minutes on standard diuretic renography in 8 cases, captopril renography showed an ipsilateral decrease and bilateral increase in glomerular filtration rate in 4 and 1, respectively, and no change in 3. In 12 of the 23 patients (52%) there was no difference in the results of captopril and diuretic renography as well as no change in differential function on standard diuretic renography during 1 1/2 years of observation. Surgical correction was performed in 4 patients in whom half-time was greater than 20 minutes and differential function was decreased on captopril renography.

CONCLUSIONS

Our preliminary study reveals that there may be a role for captopril renography for detecting renin-angiotensin system mediated compensatory mechanisms in obstructive uropathy. When such compensatory mechanisms are activated, they may be unmasked by captopril, producing 1 of 4 patterns on renography and glomerular filtration rate. Patterns may indicate different degrees of impending renal function impairment and, thus, they may become useful for determining the progression of injury, when present, and the appropriate timing of surgical intervention.

[Urinary tract infections and pregnancy]

Infection of the urinary tract is the most common type of infection in pregnant women, with a prevalence ranging from 5% to 10%. The majority of symptomatic upper urinary tract infections occur in women with pre-existent asymptomatic bacteriuria, due to the changes the urinary tract undergoes during pregnancy. In order to avoid potentially serious complications affecting maternal and fetal health, an early diagnosis followed by immediate and adequate care is mandatory. The authors have developed a procedure protocol based on the retrospective evaluation of all urinary tract infection cases during pregnancy, diagnosed in Dr. Alfredo da Costa Maternity Hospital during the year of 1994. The purpose of this protocol is to make the procedures as uniform and as adequate as possible, thus lowering the probability of complications.

Otoconia biogenesis, phylogeny, composition and functional attributes

This work consolidates data about these interesting organic crystals of vertebrate inner ears. It addresses 5 aspects of inner ear otoliths not completely understood to date: 1) embryological data that explains the formation of the crystals, 2) the significance of the organic and the inorganic phase of the otolith and the changing patterns of otoconia formation along the evolutionary tree, 3) otoliths contribution for detecting linear acceleration, 4) the effect that altered gravity and aminoglycosides have on the development and adult shape of the crystals, and the evolutionary significance of a changing shape of the crystals from primitive forms (lamprey) to high vertebrate birds and mammals is discussed, 5) functional attributes of the otolithic organs and morphological modifications of the otoliths by physical and chemical insults are presented with an extensive discussion of the most relevant literature published and available to us.

Phylogenetic relationships of platyhelminthes based on 18S ribosomal gene sequences

Nucleotide sequences of 18S ribosomal RNA from 71 species of Platyhelminthes, the flatworms, were analyzed using maximum likelihood, and the resulting phylogenetic trees were compared with previous phylogenetic hypotheses. Analyses including 15 outgroup species belonging to eight other phyla show that Platyhelminthes are monophyletic with the exception of a sequence putatively from Acoela sp., Lecithoepitheliata, Polycladida, Tricladida, Trematoda (Aspidobothrii + Digenea), Monogenea, and Cestoda (Gyrocotylidea + Amphilinidea + Eucestoda) are monophyletic groups. Catenulids form the sister group to the rest of platyhelminths, whereas a complex clade formed by Acoela, Tricladida, "Dalyellioida", and perhaps "Typhloplanoida" is sister to Neodermata. "Typhloplanoida" does not appear to be monophyletic; Fecampiida does not appear to belong within "Dalyellioida," nor Kalyptorhynchia within "Typhloplanoida." Trematoda is the sister group to the rest of Neodermata, and Monogenea is sister group to Cestoda. Within Trematoda, Aspidobothrii is the sister group of Digenea and Heronimidae is the most basal family in Digenea. Our trees support the hypothesis that parasitism evolved at least twice in Platyhelminthes, once in the ancestor to Neodermata and again in the ancestor of Fecampiida, independently to the ancestor of putatively parasitic "Dalyellioida."

The flagellar switch genes fliM and fliN of Rhodobacter sphaeroides are contained in a large flagellar gene cluster

In this work, the genes that encode the FliM and FliN proteins of Rhodobacter sphaeroides were characterized. These genes are part of a large flagellar gene cluster in which six additional open reading frames encoding products homologous to FliL, FliO, FliP, FliQ, FliR, and FlhB proteins from other bacteria were identified. The inactivation of the fliM gene gave a nonflagellate phenotype (Fla-), suggesting that FliM is required for flagellar assembly. Complementation analysis of this fliM mutant indicated that fliM and fliN transcription starts beyond the 5' end of fliK and terminates after fliN.

Vividness of visual and haptic imagery of movement

This study investigated the relationships between visual and haptic imagery of movement. A total of 338 subjects, all university students aged between 18 and 26 years, completed the Vividness of Movement Imagery Questionnaire, which evaluates capacity for visual imaging, and a modification of this questionnaire, the Vividness of Haptic Movement Imagery Questionnaire, designed to evaluate capacity for haptic imaging. Scores on the two questionnaires were significantly correlated .60.

Tumor burden and serum level of soluble CD25, CD8, CD23, CD54 and CD44 in non-Hodgkin's lymphoma

We studied the value of soluble CD25, CD8, CD23, CD54 and CD44 serum levels as tumor burden markers in lymphoma. Soluble CD25 compared with the others sCD and the usual serum factors (albumin, lactate dehydrogenase, beta 2-microglobulin, uric acid and C-reactive protein), showed the strongest correlation with the Ann Arbor stage and the number of affected localizations. sCD25 level is the most sensitive serum marker for tumor burden in lymphoma.

Study of common aerobic flora of human cerumen

Cerumen is the product of the secretion of the sebaceous, ceruminous or apocrine glands together with cells exfoliated from the cornified stratum of the epithelium of the external auditory canal (EAC). In the present study we identified and quantified common flora of human cerumen. The mean count obtained was 10(6) microorganisms per ml of cerumen suspension. In 24 pools of cerumen (33.3 per cent) the isolates were monomicrobial, Staphylococcus epidermidis (12), Corynebacterium spp (10), Staphylococcus aureus (1) and Streptococcus saprophyticum (1). In 48 pools (66.6 per cent) we found polymicrobial isolates. The most commonly isolated bacteria in these polymicrobial isolates were S. epidermidis (35) and Corynebacterium spp. (43). It is noteworthy that there were isolates of Candida albicans in three cases; in one case of Pseudomonas stutzeri, in one case of Pseudomonas aeruginosa, and, on seven occasions, of S. aureus. The organisms isolated as common bacterial components of human cerumen in our experience were similar to those found by other authors. However, the mean count was much higher. This could be related to climatic conditions and to the length of time the cerumen had remained in the external auditory canal.