Distinct functions of alternatively spliced isoforms encoded by zebrafish mef2ca and mef2cb.

In mammals, an array of MEF2C proteins is generated by alternative splicing (AS), yet specific functions have not been ascribed to each isoform. Teleost fish possess two MEF2C paralogues, mef2ca and mef2cb. In zebrafish, the Mef2cs function to promote cardiomyogenic differentiation and myofibrillogenesis in nascent skeletal myofibers. We found that zebrafish mef2ca and mef2cb are alternatively spliced in the coding exons 4-6 region and these splice variants differ in their biological activity. Of the two, mef2ca is more abundantly expressed in developing skeletal muscle, its activity is tuned through zebrafish development by AS. By 24hpf, we found the prevalent expression of the highly active full length protein in differentiated muscle in the somites. The splicing isoform of mef2ca that lacks exon 5 (mef2ca 4-6), encodes a protein that has 50% lower transcriptional activity, and is found mainly earlier in development, before muscle differentiation. mef2ca transcripts including exon 5 (mef2ca 4-5-6) are present early in the embryo. Over-expression of this isoform alters the expression of genes involved in early dorso-ventral patterning of the embryo such as chordin, nodal related 1 and goosecoid, and induces severe developmental defects. AS of mef2cb generates a long splicing isoform in the exon 5 region (Mef2cbL) that predominates during somitogenesis. Mef2cbL contains an evolutionarily conserved domain derived from exonization of a fragment of intron 5, which confers the ability to induce ectopic muscle in mesoderm upon over-expression of the protein. Taken together, the data show that AS is a significant regulator of Mef2c activity.

HOW FUNGI INTERACT WITH NEMATODE TO ACTIVATE THE PLANT DEFENCE RESPONSE TO TOMATO PLANTS.

Management of plant parasitic nematodes with nematode predators, parasites or antagonists is an eco-friendly approach that may avoid the problems arisen by the use of toxic chemicals. Fungi belonging to Trichoderma spp. are well known in literature for their role in control of plant parasitic nematodes. Root-knot nematodes (RKNs), Meloidogyne spp., are obligate parasites that cause the formation of familiar galls on the roots of many cultivated plants. The interaction between the M. incognita motile second stage juveniles (J2s) and the isolate ITEM 908 of Trichoderma harzianum was examined in its effect on the nematode infestation level of susceptible tomato plants. To gain insight into the mechanisms by which ITEM 908 interacts with nematode-infected tomato plants, the expression patterns of the genes PR1 (marker of Salycilic Acid-depending resistance signalling pathway) and JERF3 (marker of the Jasmonic Acid/Ethylene-depending resistance signalling pathway) were detected over time in: i) untreated roots; ii) roots pre-treated with the fungus; iii) roots inoculated with the nematode; iv) pre-treated and inoculated roots. Infestation parameters were checked in untreated plants and plants treated with the fungus to test the effect of the fungus on nematode infestation level and to compare this effect with the expression of the genes PR1 and JERF3, involved in induced resistance.

Pharmacological characterization of the bifunctional opioid ligand H-Dmt-Tic-Gly-NH-Bzl (UFP-505).

BACKGROUND: While producing good-quality analgesia, µ-opioid (MOP) receptor activation produces a number of side-effects including tolerance. Simultaneous blockade of δ-opioid (DOP) receptors has been shown to reduce tolerance to morphine. Here, we characterize a prototype bifunctional opioid H-Dmt-Tic-Gly-NH-Bzl (UFP-505). METHODS: We measured receptor binding affinity in Chinese hamster ovary (CHO) cells expressing recombinant human MOP, DOP, k-opioid (KOP), nociceptin/orphanin (NOP) receptors. For activation, we measured the binding of GTPγ(35)S to membranes from CHO(hMOP), CHO(hDOP), rat cerebrocortex, and rat spinal cord. In addition, we assessed 'end organ' responses in the guinea pig ileum and mouse vas deferens. RESULTS: UFP-505 bound to CHO(hMOP) and CHO(hDOP) with (binding affinity) pK(i) values of 7.79 and 9.82, respectively. There was a weak interaction at KOP and NOP (pK(i) 6.29 and 5.86). At CHO(hMOP), UFP-505 stimulated GTPγ(35)S binding with potency (pEC(50)) of 6.37 and in CHO(hDOP) reversed the effects of a DOP agonist with affinity (pK(b)) of 9.81 (in agreement with pK(i) at DOP). UFP-505 also stimulated GTPγ(35)S binding in rat cerebrocortex and spinal cord with pEC(50) values of 6.11-6.53. In the guinea pig ileum (MOP-rich preparation), UFP-505 inhibited contractility with pEC(50) of 7.50 and in the vas deferens (DOP-rich preparation) reversed the effects of a DOP agonist with an affinity (pA(2)) of 9.15. CONCLUSIONS: We have shown in a range of preparations and assays that UFP-505 behaves as a potent MOP agonist and DOP antagonist; a MOP/DOP bifunctional opioid. Further studies in dual expression systems and whole animals with this prototype are warranted.

Hormonal replacement therapy in adolescents and young women with chemo- or radio-induced premature ovarian insufficiency: Practical recommendations.

In women with premature ovarian insufficiency (POI), hormonal therapy (HT) is indicated to decrease the risk of morbidity and to treat symptoms related to prolonged hypoestrogenism. While general recommendations for the management of HT in adults with POI have been published, no systematic suggestions focused on girls, adolescents and young women with POI following gonadotoxic treatments (chemotherapy, radiotherapy, stem cell transplantation) administered for pediatric cancer are available. In order to highlight the challenging issues specifically involving this cohort of patients and to provide clinicians with the proposal of practical therapeutic protocol, we revised the available literature in the light of the shared experience of a multidisciplinary team of pediatric oncologists, gynecologists and endocrinologists. We hereby present the proposals of a practical scheme to induce puberty in prepubertal girls and a decisional algorithm that should guide the clinician in approaching HT in post-pubertal adolescents and young women with iatrogenic POI.

A novel complex regulates cardiac actin gene expression through interaction of Emb, a class VI POU domain protein, MEF2D, and the histone transacetylase p300.

Expression of the mouse cardiac actin gene depends on a distal enhancer (-7 kbp) which has been shown, in transgenic mice, to direct expression to embryonic skeletal muscle. The presence of this distal sequence is also associated with reproducible expression of cardiac actin transgenes. In differentiated skeletal muscle cells, activity of the enhancer is driven by an E box, binding MyoD family members, and by a 3' AT-rich sequence which is in the location of a DNase I-hypersensitive site. This sequence does not bind MEF2 proteins, or other known muscle transcription factors, directly. Oct1 and Emb, a class VI POU domain protein, bind to consensus sites on the DNA, and it is the binding of Emb which is important for activity. Emb binds as a major complex with MEF2D and the histone transacetylase p300. The form of Emb present in this complex and as a major form in muscle cell extracts is longer (80 kDa) than that previously described. These results demonstrate the importance of this novel complex in the transcriptional regulation of the cardiac actin gene and suggest a potential role in chromatin remodeling associated with muscle gene activation.

Specific binding to vitamin D response elements of chicken intestinal DNA-binding activity is not related to the vitamin D receptor.

In this report we confirm that the putative vitamin D response element (VDRE), located between -320 and -306 in the chicken calbindin-D28K gene, is not a binding site for the vitamin D3 receptor (VDR). In examining the ability of chicken intestinal nuclear extracts (CINE) to bind known VDREs, we observed a specific VDRE-binding activity, which is distinct from VDR. In fact, VDR-depleted CINE retains the ability to bind the rat osteocalcin VDRE. The VDRE-binding activity binds DNA with high affinity and contacts it at the same guanine residues as VDR. Its specificity in binding structural variants of the AGGTCA repeat is broader than that of VDR, as direct repeats spaced by 3, 4, and 5 base pairs are almost equally effective competitors when added to the probe in molar excess. Palindromic arrangements of the same motif are lower affinity competitors. The retinoid-X receptor is involved in the binding complex, as incubation of CINE with antibody to retinoid-X receptor results in a quantitative supershift. Antibodies to retinoic acid receptors (RAR alpha and -beta), T3 receptor, or chicken ovalbumin up-stream promoter-transcription factor had no apparent effect. These data suggest that species specificity is a relevant aspect of VDR/VDRE recognition, and that a novel factor(s), different from VDR, might be involved in the effect of vitamin D on gene expression.

The in vivo form of the murine class VI POU protein Emb is larger than that encoded by previously described transcripts.

The class VI POU domain family member known as Emb in the mouse (rat Brn5 or human mPOU/TCFbeta1) is present in vivo as a protein migrating at about 80 kDa on western blots, considerably larger than that predicted (about 42 kDa) from previously cloned coding sequences. By RT-PCR and 5' RACE strategies a full-length Emb sequence, Emb FL, is now identified. Shorter sequences encoding the -COOH terminal, and an -NH(2) terminal isoform, EmbN, were also isolated. Comparisons of Emb coding sequences between species, including the full-length zebra fish, POU(c), are presented, together with a compilation of the multiple transcripts produced by alternative splicing and the presence of different transcriptional start and stop sites, from the Emb gene.

The diagnostic value of imaging the patient with dizziness. A Bayesian approach.

BACKGROUND: Imaging studies are routinely used in the evaluation of patients with dizziness. A principal concern of the ordering physician is to rule out a cerebellopontine angle (CPA) mass. The incidence of such masses in patients presenting with dizziness is quite low, however, raising the question of the value of imaging this population. OBJECTIVE: To calculate the probability, using Bayes theorem, that a given patient with dizziness has a CPA mass. DESIGN: Meta-analysis of epidemiological data on CPA masses and of studies reporting the incidence of otologic symptoms in patients with these masses. We also conducted a study of consecutive patients with dizziness to determine the frequency of asymmetric hearing loss in this population. These data were combined in applications of Bayes theorem to calculate disease probabilities. RESULTS: The probability that a patient with dizziness has a CPA mass is 0.0004, indicating that 2500 imaging studies would have to be performed to identify 1 CPA mass. If patients with subjectively normal hearing are investigated (ie, those with isolated dizziness), the probability is 0.000107, indicating that 9307 scans would have to be performed to identify 1 CPA mass. If the search is restricted to those patients with dizziness and asymmetric hearing loss (the patients usually felt to be high risk), the probability is 0.00156, indicating that 638 scans would have to be performed to identify 1 CPA mass. CONCLUSIONS: Even when studying patients with dizziness and asymmetric hearing loss, the probability of identifying a CPA mass is sufficiently low that we do not feel imaging is generally warranted. When faced with a patient with dizziness, we recommend a careful neurologic and otologic examination. If abnormalities are detected on examination that suggest central nervous system disease or invasive otologic disease, imaging should be pursued as appropriate. In cases of acute vertigo, if the patient is at high risk for cerebrovascular disease by virtue of age and additional risk factors, imaging should probably be pursued. For the remainder of patients, if progression of hearing loss is not documented, we do not believe imaging is warranted. Progressive hearing loss with abnormal speech reception thresholds probably warrants a magnetic resonance imaging scan of the internal auditory canals.

Incidence and prevalence trends of HIV infection in intravenous drug users attending treatment centers in Milan and northern Italy, 1986-1990.

To assess the incidence and time trends of human immunodeficiency virus (HIV) infection among intravenous drug users (IVDUs) and to evaluate the opportunities for prevention, we studied IVDUs recruited from 23 drug dependence treatment centers in Milan and Northern Italy. Participants were screened for HIV antibodies, and seronegative subjects were enrolled. A preventive intervention, based on counseling and HIV antibody testing, was done, and participants were invited to the centers for follow-up visits. We enrolled 1,532 subjects between 1 January 1987 and 31 October 1990, and we observed 901 subjects for an average of 15.9 months. Forty-one cases of HIV infection occurred, giving a seroconversion rate of 6.1% in 1987, 4.1% in 1988, 2.2% in 1989, and 1.6% in 1990. HIV prevalence decreased from 54% in 1986 to 49% in 1989. Incidence rates were higher in areas with high prevalence. During follow-up, 35 to 55% of the subjects stopped injecting heroin intravenously altogether, and those who did not stop decreased the frequency of syringe sharing. This is probably the reason for the decline in seroconversion rates, while the apparent decline in prevalence may be due to the entry of new seronegative individuals and/or to differential withdrawal of HIV-positive individuals from the IVDU population to the heterosexual (non-IVDU) population.

Picture naming and progression of Alzheimer's disease: an analysis of error types.

Seven patients affected by Dementia of the Alzheimer Type (DAT) took part in a longitudinal study aimed at assessing the qualitative and quantitative evolution of picture naming impairment. The follow-up lasted 6-36 months and the patients were examined at intervals of 6 months or longer. We found that the absolute number of lexical-semantic errors tended to be constant or to rise slightly until an advanced stage of DAT severity was reached. However, the proportion of errors of the lexical-semantic type in relation to the overall number of errors showed a decline as the disease progressed, with empty and unrelated responses being increasingly observed. Visual errors were generally a minority; they were produced in different proportions for each patient but did not vary greatly over time. For the observed patients, the proportion of lexical and semantic errors was inversely related to the overall naming performance, following a negative logarithmic function. This finding was replicated analysing cross-sectional data from another 24 DAT patients who were given the same naming task.

Central neurocytoma: An unusual intraventricular tumor.

A case of central neurocytoma occurring in a 22-year-old man is presented. This tumor is generally considered to be benign in appearance, nonrecurrent, and amenable to surgical resection. However, this particular neurocytoma demonstrated anaplastic features, raising the issue of malignancy and the need for additional modes of treatment. Implicated factors and possible optimal treatment for this tumor are discussed.

Is SIB or BNP better than MMSE in discriminating the cognitive performance of severely impaired elderly patients?

The sensitivity of the Mini Mental State Evaluation (MMSE) in severely impaired patients is reduced by a floor effect and limited score range. The Severe Impairment Battery (SIB) and Preliminary Neuropsychological Battery (BNP) may be valid alternatives. We studied a group of 37 severely compromised elderly inpatients to investigate the usefulness of these two test batteries as alternatives to the MMSE. Both proved reliable, but only the SIB had a wider distribution of results with respect to the MMSE in the lower score range. The BNP, that might be thought easier to perform being a simple verification task, could actually not be completed by the most compromised patients. The SIB seems better able than the MMSE to provide cognitive profile in the three diagnostic categories into which patients were subdivided (Psychogeriatric, Psychorganic, Mentally Retarded). We conclude that it may be useful to test patients with the SIB when they yield a MMSE score lower than 10-12 points.

Effects of protein and vitamin B deficiency on blood parameters and myenteric neurons of the colon of rats.

The aims of this work were to evaluate the effects of the deficient ingestion of protein and vitamin B on the biochemical and hematologic parameters and on the NADH- and NADPH-diaphorase positive myenteric neurons. The control animals (n=10) received commercial chow and the experimental rats (n=10) received chow with protein level reduced to 8% during 120 days. At the time of killing blood was collected for assessment of the blood and hematologic parameters and the ascending colon for quantitative analysis of the neurons of the myenteric plexus. It was observed that the reduction of the protein level to 8% coupled to the reduction of the levels of vitamin B in adult rats neither led to qualitative or quantitative changes on red or white blood cells, nor decreased globulin levels, induced the formation of edema or gave rise to clinical signs typical of protein or vitamin B deficiency. On the other hand, the experimental protocol led to less weight gain, change on the body composition with fat deposition; decrease of the values of serum total protein and albumin; reduction of the area of colon and density of nitrergic and NADH-diaphorase myenteric neurons inferior to the expected.

[Morphological study of human arachnoid granulations with reference to their classification]. / Estudo morfológico das granulações aracnóides humanas com referência a sua classificação.

Stereomicroscopic and microscopic study showed human arachnoid granulations with different morphology that we classified in simple and lobate. Simple granulations were small and completely involved by fibrous capsule that delimited a continuous subdural space from the pedicle to the apex. Lobate granulations were bigger than the simple; in the apex the fibrous capsule was thinner than in other regions, and fused with granulation periphery causing interruption of subdural space. Simple granulations might be an initial development stage; lobate granulations would represent a higher development stage, with ideal morphologic structure for absorption of the CSF.

Quantitative study of the myenteric plexus of the stomach of rats with streptozotocin-induced diabetes.

The purpose of the present study was to investigate the morphological and quantitative alterations of the myenteric plexus neurons of the stomach of rats with streptozotocin-induced chronic diabetes and compare them to those of non-diabetic animals. Samples from the body of the stomach were used for whole-mount preparations stained with NADH-diaphorase and for histological sections stained with hematoxylin-eosin. It was observed that diabetes cause a significant decrease on the number of neurons.

Regional differences in the number and type of myenteric neurons of the ileum of rats: a comparison of techniques of the neuronal evidentiation.

We carried out this study with the purpose of analyzing the density of neurons of the myenteric plexus in the mesenteric, intermediate and antimesenteric regions of the ileum of rats. Whole-mounts stained with four different techniques were employed. Through countings under optic microscope in an area of 8.96 mm2 we found the following neuronal means with the techniques of Giemsa, NADH-diaphorase histochemistry, NADPH-diaphorase and acetylcholinesterase, respectively: mesenteric region 2144.40+/-161.05, 1657.80+/-88.23, 473.80+/-19.62, 905.25+/-22.40; intermediate region 1790.60+/-128.24, 1265.20+/-141.17, 371.30+/-27.84, 770.25+/-33.12; antimesenteric region 1647.0+/-76.67, 981.80+/-68.04, 298.50+/-22.75, 704.50+/-69.38. We conclude that there is a variation of neuronal density around the intestinal circumference and this fact independs on the technique used to stain the neurons, and that in a single region the neuronal density varies with the technique employed. We also call attention for the identification of the site were countings were carried out, so that the results of research in this area are not compromised.

Morphological and quantitative study of the myenteric plexus of the ascending colon of rats subjected to proteic desnutrition.

We carried out this study with the purpose of contributing on the effects of the proteic desnutrition on the morphological aspects and quantitative analysis of the neurons in the myenteric plexus of the ascending colon of adult Rattus norvegicus. Twenty adult rats were divided into two groups: in one of them, we offered a normal ration with proteic level of 22% (control group) and in the other, a ration with a proteic level of 8% (experiment group) during 120 days. We did the whole-mount preparations for the ascending colon and stained them with the Giemsa technique and the histochemical technique of NADH-diaphorase. The rats with proteic desnutrition showed a body weight, on average, to be 35.1% less than those of the control group, and the colon was on average, 26.8% shorter and 6.7% narrower. Thus, it was to be expected that the colon of animals with proteic desnutrition had a neuronal density 31.62% greater than the rats of the control group. Nevertheless, the difference with the Giemsa technique was on average 18.4%, demonstrating a mean neuronal loss of 13.25%.

Neuron number in the myenteric plexus of the ascending colon of rats. A comparative study using two staining techniques.

We carried out this study with the purpose of comparing the neuronal density in antimesocolic and intermediate regions of the colon of rats. We used the ascending colon of ten seven-months old Wistar rats. With the Giemsa method we found 29,046 neurons/cm2 on the antimesocolic region and 30,968 neurons/cm2 on the intermediate regions. With the NADH-diaphorase technique 12,308 neurons/cm2 on the antimesocolic regions and 8798 neurons/cm2 on the intermediate regions were evidenced. The number of NADH-diaphorase positive neurons is significantly less than the number of Giemsa-stained neurons and that this difference is enhanced on the intermediate regions of the intestinal circumference. Therefore, to compare the number of neurons of an intestinal segment of a same species at the same age, it is necessary to take into consideration the technique employed and the region of the intestinal circumference from where the sample was obtained.

Number and size of myenteric neurons of the duodenum of adult rats with acute diabetes.

This study had as its purpose to assess the effects of acute diabetes induced by streptozotocin (35 mg/kg body weight) on the number and size of the myenteric neurons of the duodenum of adult rats considering equally the antimesenteric and intermediate regions of the intestinal circumference. Experimental period extended for a week. Neuronal counts were carried out on the same number of fields of both regions of the duodenal circumference and measurements of neuronal and nuclear areas on equal numbers of cells. Number and size of the myenteric neurons stained with Giemsa were not significantly different between groups. On the other hand, the proportion of NADH-positive neurons increased from 18.54% on the controls to 39.33% on the diabetics. The authors discuss that this increased reactivity probably results from a greater NADH/NAD+ ratio, described in many tissues of diabetic animals, which has consequences on the modulation of the enzymes that use these cofactors and whose activity is detected by the NADH-diaphorase technique.

Evaluation of the areas of neuronal cell bodies and nuclei in the myenteric plexus of the duodenum of adult rats.

This study compared the areas of cell body and nucleus profiles of the myenteric neurons in the antimesenteric and intermediate regions of the duodenum of adult rats. Five male rats were used. The duodenum was removed and dissected to whole-mount preparations, which were stained by the Giemsa technique. The areas of cell body and nucleus profiles of 100 neurons, 50 from each region, of each animal, were assessed with image analyser. Based on the global mean+/-SD of the areas of cell body profiles, neurons were labelled as small, medium or large. It was observed that the neurons did not differ significantly in size or incidence between the antimesenteric and intermediate regions. However, the nuclei of the small and medium neurons were significantly smaller in the latter region. It is discussed that the smaller nuclear size could be related to the cell bodies being slightly smaller on this region and to a possible smaller biosynthetic activity which would influence nuclear size.