Spatial accumulation of flood-driven riverside litter in two Northern Atlantic Rivers

The escalation of litter accumulation in aquatic environments is recognized as an emerging global concern. Although rivers represent the main conduits for land-based waste into the oceans, the spatial dynamics of litter accumulation in these systems remain poorly investigated, especially after hydro-climatic extreme events. Floods have been identified as major drivers of litter mobilization, including macroplastics, within rivers. However, predicting flood-induced litter accumulation along riverbanks is complex due to the cumulative interplay of multiple environmental (geomorphological and riparian) and anthropogenic factors. Using empirical data collected from 14 stream reaches in two Northern Atlantic rivers in Portugal, our study evaluates which factors, among geomorphological, riparian, and anthropogenic descriptors, best drive riverside litter accumulation after floods. Taking into account the longitudinal gradient and the spatial heterogeneity of the studied reaches, our study enhances how the accumulation and characteristics (type, size) of riverside litter vary across a rural-urban continuum. Our model reveals that the combination of the human population density and the stream slope at river reach showed the highest explanatory power for the accumulation of riverside litter. Our findings indicate that litter tends to be retained close to the source, even under flood conditions. We also found that the structure of riparian vegetation showed low explanatory power for litter accumulation. However, riparian trapping could be influenced by litter input (density and type) which varies with anthropogenic activities. This work highlights the importance of gathering field data to identify critical areas of riverside litter accumulation within river basins. Our findings can further support environmental managers in designing and implementing effective cleanup campaigns and implementing plastic recovery strategies at specific areas. Nevertheless, it is crucial to enhance coordinated efforts across the entire value chain to reduce plastic pollution, promote innovative approaches for plastic litter valorization, and establish effective prevention pathways.

Evolutionary analysis of cellular reduction and anaerobicity in the hyper-prevalent gut microbe Blastocystis

Blastocystis is the most prevalent microbial eukaryote in the human and animal gut, yet its role as commensal or parasite is still under debate. Blastocystis has clearly undergone evolutionary adaptation to the gut environment and possesses minimal cellular compartmentalization, reduced anaerobic mitochondria, no flagella, and no reported peroxisomes. To address this poorly understood evolutionary transition, we have taken a multi-disciplinary approach to characterize Proteromonas lacertae, the closest canonical stramenopile relative of Blastocystis. Genomic data reveal an abundance of unique genes in P. lacertae but also reductive evolution of the genomic complement in Blastocystis. Comparative genomic analysis sheds light on flagellar evolution, including 37 new candidate components implicated with mastigonemes, the stramenopile morphological hallmark. The P. lacertae membrane-trafficking system (MTS) complement is only slightly more canonical than that of Blastocystis, but notably, we identified that both organisms encode the complete enigmatic endocytic TSET complex, a first for the entire stramenopile lineage. Investigation also details the modulation of mitochondrial composition and metabolism in both P. lacertae and Blastocystis. Unexpectedly, we identify in P. lacertae the most reduced peroxisome-derived organelle reported to date, which leads us to speculate on a mechanism of constraint guiding the dynamics of peroxisome-mitochondrion reductive evolution on the path to anaerobiosis. Overall, these analyses provide a launching point to investigate organellar evolution and reveal in detail the evolutionary path that Blastocystis has taken from a canonical flagellated protist to the hyper-divergent and hyper-prevalent animal and human gut microbe.

Follow-up investigation into Cryptosporidium prevalence and transmission in Western European dairy farms

Cryptosporidium parvum is an enteric parasite and a major contributor to acute enteritis in calves worldwide, causing an important economic burden for farmers. This parasite poses a major public health threat through transmission between livestock and humans. Our previous pilot study in Western Europe revealed a high prevalence of Cryptosporidium in calves of dairy farms. In the sequel study herein, 936 faecal samples were collected from the same 51 dairy farms across Belgium, France, and the Netherlands. Following DNA extraction, Cryptosporidium screening was carried out using nested-PCR amplification targeting the SSU rRNA gene. All positive samples were sequenced, and phylogenetic analyses were used to identify the Cryptosporidium spp. present. The 60 kDa glycoprotein (gp60) gene was also sequenced to determine the C. parvum subtypes present. Prevalence of Cryptosporidium ranged from 23.3% to 25%, across the three countries surveyed. The parasite was found in most of the farms sampled, with 90.2% testing positive. Cryptosporidium parvum, C. bovis, C. ryanae and C. andersoni were all identified, with the former being the most predominant, representing 71.4% of all infections. Cryptosporidium parvum was associated with pre-weaned calves, while other species were associated with older animals. Subtyping of gp60 gene revealed nine subtypes, eight of which have previously been reported to cause clinical disease in humans. Similarly to the first study, vertical transmission was not a major contributor to Cryptosporidium spread. Our study highlights the need for further investigation into cryptosporidiosis transmission, and future studies will require a One Health approach to reduce the impact of this disease.

Cross-Border Investigations on the Prevalence and Transmission Dynamics of Cryptosporidium Species in Dairy Cattle Farms in Western Mainland Europe

Cryptosporidium is an apicomplexan parasitic protist, which infects a wide range of hosts, causing cryptosporidiosis disease. In farms, the incidence of this disease is high in animals such as cows, leading to extensive economic loss in the livestock industry. Infected cows may also act as a major reservoir of Cryptosporidium spp., in particular C. parvum, the most common cause of cryptosporidiosis in these animals. This poses a risk to the trading of livestock, to other farms via breeding centres, and to human health. This study is a part of a global project aimed at strategies to tackle cryptosporidiosis. To reach this target, it was essential to determine whether prevalence was dependent on the studied countries or if the issue was borderless. Indeed, C. parvum occurrence was assessed across dairy farms in certain regions of Belgium, France, and the Netherlands. At the same time, the animal-to-animal transmission of the circulating C. parvum subtypes was studied. To accomplish this, we analysed 1084 faecal samples, corresponding to 57 dairy farms from all three countries. To this end, 18S rRNA and gp60 genes fragments were amplified, followed by DNA sequencing, which was subsequently used for detection and subtyping C. parvum. Bioinformatic and phylogenetic methods were integrated to analyse and characterise the obtained DNA sequences. Our results show 25.7%, 24.9% and 20.8% prevalence of Cryptosporidium spp. in Belgium, France, and the Netherlands respectively. Overall, 93% of the farms were Cryptosporidium positive. The gp60 subtyping demonstrated a significant number of the C. parvum positives belonged to the IIa allelic family, which has been also identified in humans. Therefore, this study highlights how prevalent C. parvum is in dairy farms and further suggests cattle as a possible carrier of zoonotic C. parvum subtypes, which could pose a threat to human health.

Nitric oxide (NO) elicits aminoglycoside tolerance in Escherichia coli but antibiotic resistance gene carriage and NO sensitivity have not co-evolved

The spread of multidrug-resistance in Gram-negative bacterial pathogens presents a major clinical challenge, and new approaches are required to combat these organisms. Nitric oxide (NO) is a well-known antimicrobial that is produced by the immune system in response to infection, and numerous studies have demonstrated that NO is a respiratory inhibitor with both bacteriostatic and bactericidal properties. However, given that loss of aerobic respiratory complexes is known to diminish antibiotic efficacy, it was hypothesised that the potent respiratory inhibitor NO would elicit similar effects. Indeed, the current work demonstrates that pre-exposure to NO-releasers elicits a > tenfold increase in IC₅₀ for gentamicin against pathogenic E. coli (i.e. a huge decrease in lethality). It was therefore hypothesised that hyper-sensitivity to NO may have arisen in bacterial pathogens and that this trait could promote the acquisition of antibiotic-resistance mechanisms through enabling cells to persist in the presence of toxic levels of antibiotic. To test this hypothesis, genomics and microbiological approaches were used to screen a collection of E. coli clinical isolates for antibiotic susceptibility and NO tolerance, although the data did not support a correlation between increased carriage of antibiotic resistance genes and NO tolerance. However, the current work has important implications for how antibiotic susceptibility might be measured in future (i.e. ± NO) and underlines the evolutionary advantage for bacterial pathogens to maintain tolerance to toxic levels of NO.

The cytochrome bd-I respiratory oxidase augments survival of multidrug-resistant Escherichia coli during infection

Nitric oxide (NO) is a toxic free radical produced by neutrophils and macrophages in response to infection. Uropathogenic Escherichia coli (UPEC) induces a variety of defence mechanisms in response to NO, including direct NO detoxification (Hmp, NorVW, NrfA), iron-sulphur cluster repair (YtfE), and the expression of the NO-tolerant cytochrome bd-I respiratory oxidase (CydAB). The current study quantifies the relative contribution of these systems to UPEC growth and survival during infection. Loss of the flavohemoglobin Hmp and cytochrome bd-I elicit the greatest sensitivity to NO-mediated growth inhibition, whereas all but the periplasmic nitrite reductase NrfA provide protection against neutrophil killing and promote survival within activated macrophages. Intriguingly, the cytochrome bd-I respiratory oxidase was the only system that augmented UPEC survival in a mouse model after 2 days, suggesting that maintaining aerobic respiration under conditions of nitrosative stress is a key factor for host colonisation. These findings suggest that while UPEC have acquired a host of specialized mechanisms to evade nitrosative stresses, the cytochrome bd-I respiratory oxidase is the main contributor to NO tolerance and host colonisation under microaerobic conditions. This respiratory complex is therefore of major importance for the accumulation of high bacterial loads during infection of the urinary tract.

Resveratrol administration increases Transthyretin protein levels ameliorating AD features- importance of transthyretin tetrameric stability

Previous in vivo work showed that resveratrol has beneficial effects in the AD pathology, resulting in increased expression of transthyretin (TTR). TTR binds Aβ peptide avoiding its aggregation and toxicity, and is reduced in the CSF and plasma, in AD. Further, resveratrol binds TTR, stabilizing the native TTR tetrameric structure. To further explore the mechanism of neuroprotection conferred by TTR in AD, resveratrol was administrated, in the diet, to 5-8 months old AD transgenic female mice carrying just one copy of the mouse TTR gene, for two months. Effects in brain Aβ burden were evaluated by immunohistochemistry, and in total brain Aβ levels by ELISA, showing a striking decrease in both parameters in treated animals. In addition, total brain LRP1 protein levels were increased in treated animals, although its gene expression was unaltered. To further understand the mechanism(s) underlying such improvement in AD features, we measured TTR plasma levels showing that TTR increased in resveratrol-treated mice, whereas liver TTR gene transcription was not altered. These results strengthen the stability hypothesis, which postulates that TTR is unstable in AD leading to accelerated clearance and lower levels. Therefore, resveratrol which stabilizes the TTR tetramer results in TTR normalized clearance, thus increasing the protein plasma levels. In turn, stabilized TTR binds more strongly to Aβ peptide, avoiding its aggregation. Our results represent a step forward to the understanding of the mechanism underlying TTR protection in AD and highlight the possibility of using TTR stabilization as a therapeutic target in AD.

Mirabegron relaxes urethral smooth muscle by a dual mechanism involving β3 -adrenoceptor activation and α1 -adrenoceptor blockade

LINKED ARTICLE

This article is commented on by Michel, M. C., pp. 429-430 of this issue. To view this commentary visit http://dx.doi.org/10.1111/bph.13379.

BACKGROUND AND PURPOSE

Mirabegron is the first β3 -adrenoceptor agonist approved for treatment of overactive bladder syndrome. This study aimed to investigate the effects of β3 -adrenoceptor agonist mirabegron in mouse urethra. The possibility that mirabegron also exerts α1 -adrenoceptor antagonism was also tested in rat smooth muscle preparations presenting α1A - (vas deferens and prostate), α1D - (aorta) and α1B -adrenoceptors (spleen).

EXPERIMENTAL APPROACH

Functional assays were carried out in mouse and rat isolated tissues. Competition assays for the specific binding of [(3) H]prazosin to membrane preparations of HEK-293 cells expressing each of the human α1 -adrenoceptors, as well as β-adrenoceptor mRNA expression and cyclic AMP measurements in mouse urethra, were performed.

KEY RESULTS

Mirabegron produced concentration-dependent urethral relaxations that were shifted to the right by the selective β3 -adrenoceptor antagonist L-748,337 but unaffected by β1 - and β2 -adrenoceptor antagonists (atenolol and ICI-118,551 respectively). Mirabegron-induced relaxations were enhanced by the PDE4 inhibitor rolipram, and the agonist stimulated cAMP synthesis. Mirabegron also produced rightward shifts in urethral contractions induced by the α1 -adrenoceptor agonist phenylephrine. Schild regression analysis revealed that mirabegron behaves as a competitive antagonist of α1 -adrenoceptors in urethra, vas deferens and prostate (α1A -adrenoceptor, pA2  ≅ 5.6) and aorta (α1D -adrenoceptor, pA2  ≅ 5.4) but not in spleen (α1B -adrenoceptor). The affinities estimated for mirabegron in functional assays were consistent with those estimated in radioligand binding with human recombinant α1A - and α1D -adrenoceptors (pKi  ≅ 6.0).

CONCLUSION AND IMPLICATIONS

The effects of mirabegron in urethral smooth muscle are the result of β3 -adrenoceptor agonism together with α1A and α1D -adrenoceptor antagonism.

Skull osteosarcoma: illustrated review

A case of conventional intramedullary osteosarcoma (epithelioid subtype) with 10 years of evolution and another of high grade surface osteosarcoma of the chondroblastic type, both in the skull, gave rise to several diagnostic and therapeutic difficulties. Key points concerning the definition, classification, imaging, clinical series data and treatment options available for skull osteosarcoma are highlighted.

Association between early detection of soluble TNF-receptors and mortality in burn patients

OBJECTIVES

To describe early sequential profiling of circulating levels of tumor necrosis factor alpha (TNF-alpha), TNF-1 and TNF-2 soluble receptors (sTNFR1 and sTNFR2), and of endothelin (ET-1) in patients with severe burn injury, and its association with mortality.

DESIGN

Prospective study.

SETTING

Intensive Care Burn Unit at a community hospital.

PATIENTS

Twenty patients with total burn surface area (TBSA)> or = 30%.

INTERVENTIONS

None.

MEASUREMENTS AND RESULTS

Patients were enrolled within 6 h from the injury. Blood samples were drawn at zero, 6, 12, and 24 h for sequential ELISA measurement of plasma marker levels. Data are expressed as mean+/-SD. Age, TBSA, and inhalation injury were not significantly different between survivors ( n=9; 30+/-13 years, TBSA 40+/-12%) and nonsurvivors ( n=11, 38+/-15 years, TBSA 56+/-20%). sTNFR1 levels were increased in nonsurvivors (2937+/-1676 pg/ml; 4548+/-1436 pg/ml) as compared to survivors (1313+/-561 pg/ml; 2561+/-804 pg/ml) at 6 h and 24 h, respectively ( P=0.01 and 0.002). sTNFR2 levels were significantly increased in nonsurvivors (4617+/-1,876 pg/ml vs 2611+/-1,326 pg/ml) only at 6 h ( P=0.015). TNF-alpha and ET-1 levels were not different between nonsurvivors and survivors. After adjustment for TBSA, sTNFR1 and sTNFR2 remained significantly higher in nonsurvivors.

CONCLUSION

Early and progressive increase in sTNFR1 and sTNFR2 levels is associated with higher risk for poor outcome in severely burned patients.

[The use of a therapeutic toy, as a tool for nursing intervention, in the preparation of children for blood sampling]

This study is almost an experiment with the objective to verify the effect of the Therapeutic Play on preschool children during blood collect for laboratory tests. The sample consisted of 42 children divided into control and experimental groups. All the children had their behavior observed and only the children of the experimental group were prepared for the Therapeutic Play. The results were analyzed comparing the children's behavior with the groups and showed that arrangement with the Therapeutic Play was effective in the comprehension of the procedure and in the control of their behavioral reactions.

NPY regulates catecholamine secretion from human adrenal chromaffin cells

The aim of the present work was to find out whether NPY synthesized in human adrenal chromaffin cells controls in an autocrine/paracrine fashion the release of catecholamines by these cells. Accordingly, the constitutive and regulated release of both NPY and catecholamines was measured simultaneously in cultured human chromaffin cells. In addition, by using both RT-PCR and a combination of specific agonists and antagonists, we characterized the expression of NPY receptors on these cells as well as their pharmacology. Our results were as follows. 1) Human chromaffin cells constitutively secrete NPY. 2) Nicotine elicits a rapid increase in the release of both catecholamines and NPY; this release of NPY is more sustained than that of catecholamines. 3) RT-PCR shows expression of Y1, Y2, Y4, and Y5 receptor mRNA by chromaffin cells; these receptors are functional, as various receptor specific agonists elicit an increase in intracellular calcium. 4) Peptide YY, in contrast to NPY, is not able to stimulate the release of catecholamines. This finding was corroborated by the observation that no receptor-specific antagonists were able to reduce constitutive catecholamine release, whereas an NPY-immunoneutralizing antibody markedly attenuated the secretion. Taken together, these data suggest that NPY originating from the adrenal medulla locally enhances the secretion of catecholamines, presumably by acting via the putative y3 receptor.

Is TTF1 a good immunohistochemical marker to distinguish primary from metastatic lung adenocarcinomas?

To evaluate the immunohistochemical expression of thyroid transcription factor 1 (TTF1) in primary and metastatic pulmonary adenocarcinomas, and test the diagnostic accuracy of this antibody, two surgical pathologists independently evaluated 34 cases of adenocarcinomas in the lung without clinical data and tried to distinguish between primary and metastatic cases using histological criteria exclusively. Thirteen cases were primary in the lung and 21 were metastases of extrapulmonary adenocarcinomas: 6 from the endometrium, 4 from the ovary, 3 from the colon, 2 from the kidney, 2 from the breast, 2 from the liver and 1 from the prostate. Afterward, the immunoreactivity of TTF1 in these neoplasms was evaluated and correlated with morphological and clinical data. The two pathologists were able to diagnose only 5 out of 13 cases of primary lung adenocarcinomas (sensitivity of 38.46%) and also misdiagnosed two primary malignancies as metastases. After correlation with TTF1 data, the sensitivity increased to 61.53%. The specificity of TTF1 was 100%. In conclusion, TTF1 is a highly specific marker for primary lung adenocarcinomas, and should be included in a panel of antibodies for the differential diagnosis between primary and metastatic adenocarcinomas of the lung.

[Protocol for the preparation of preschool children to venous puncture using therapeutic play]

This exploratory-descriptive study aims at elaborating a protocol, using therapeutic play, for the preparation of preschool children to venous puncture and also at testing its efficiency and applicability. The children that attended the play session were more cooperative when they were punctured. They understood the need and technical aspects of this clinical procedure; manifested their feelings, elaborated familiar and hospital situations that resulted in a better relationship with the other children and the nursing team. Authors concluded that this protocol is feasible and useful and suggested that it should be incorporated in the nursing care plan to hospitalized children.

L-5-Hydroxytryptophan in the prophylaxis of chronic tension-type headache: a double-blind, randomized, placebo-controlled study. For the Portuguese Head Society

A parallel, randomized, double-blind trial is reported, in which 78 patients with chronic tension-type headaches were treated with L-5-hydroxytryptophan (5-HTP) (n = 43) or placebo (n = 35) for 8 weeks, after a washout period of 2 weeks and with a follow-up period of a further 2 weeks. Five patients dropped out (1 with placebo and 4 with 5-HTP), 1 was excluded due to noncompliance, and in 7 treatment was suspended due to adverse events (3 with placebo and 4 with 5-HTP), yielding a final number for evaluation of 65 patients. In comparison with the group treated with placebo, there was no statistically significant change in the number of days with headache or in headache intensity in the group treated with 5-HTP, 300 mg per day; however, there was a significant decrease in the consumption of analgesics. During the 2 weeks after treatment, there was a significant decrease in the number of days with headache. Subjective opinion during this latter period was also favorable to 5-HTP.

Inhibitory effect of high [Mg2+] on the vasopressin-stimulated hydroosmotic permeability of the isolated perfused cortical collecting duct

High magnesium concentration inhibits the effect of arginine vasopressin (AVP) on smooth muscle contraction and platelet aggregation and also influences hepatocyte AVP receptor binding. The aim of this study was to determine the role of magnesium concentration [Mg2+] in AVP-stimulated water transport in the kidney collecting duct. The effect of low and high peritubular [Mg2+] on the AVP-stimulated osmotic water permeability coefficient (Pf) was evaluated in the isolated perfused rabbit cortical collecting duct (CCD). Control tubules bathed and perfused with standard Ringer bicarbonate solution containing 1 mM Mg2+ presented a Pf of 223.9 +/- 27.2 microm/s. When Mg2+ was not added to the bathing solution, an increase in the AVP-stimulated Pf to 363.1 +/- 57.2 microm/s (P<0. 05) was observed. An elevation of Mg2+ to 5 mM resulted in a decrease in Pf to 202.9 +/- 12.6 microm/s (P<0.05). This decrease in the AVP-stimulated Pf at 5 mM Mg2+ persisted when the CCDs were returned to 1 mM Mg2+, Pf = 130.2 +/- 20.3 microm/s, and was not normalized by the addition of 8-[4-chlorophenylthio]-adenosine 3', 5'-cyclic monophosphate, a cAMP analogue, to the preparation. These data indicate that magnesium may play a modulatory role in the action of AVP on CCD osmotic water permeability, as observed in other tissues.

Evidence of sex related differences in the effects of calcium channel blockers on neuroleptic-induced catalepsy in mice

1. Calcium channel blockers (CCBs) are reported to affect extrapyramidal motor behavior in mammals. Since sex related differences are a common feature in the pharmacological properties of several centrally active drugs, the authors decided to investigate the effects of verapamil (VER), flunarizine (FLU) and nimodipine (NIM), three pharmacologically different CCBs, on neuroleptic-induced catalepsy in male and female albino mice. 2. Catalepsy was induced with haloperidol (0.75 mg/kg, i.p.) and measured at 30-min intervals by means of a bar test. Drugs (or appropriate vehicle, for the controls) were injected i.p. 20 min before haloperidol, with each animal being used only once. 3. VER (1, 5 and 10 mg/kg) did not significantly affect catalepsy in male mice. In females, however, a significant attenuation of catalepsy was found at the two higher doses. 4. FLU (1, 5 and 10 mg/kg) did not significantly affect catalepsy in male mice, whilst a significant attenuation was observed in females with the doses of 1 and 5 mg/kg (but not with the dose of 10 mg/kg). 5. NIM (3, 10 and 30 mg/kg) potentiated neuroleptic-catalepsy in males at the doses of 10 and 30 mg/kg. In females, however, only the higher dose of NIM caused a potentiation of catalepsy. 6. These results demonstrate the existence of sex related differences in the extrapyramidal effects of CCBs in mice. Further, this sex related effect might depend, among other factors, on the particular channel involved.

Influence of concurrent heroin and cocaine abuse on the adrenergic and serotonergic systems in man

Drugs of abuse interfere with the adrenergic activity at the periphery and the study of their effects in vivo at this level may contribute to understand the central mechanisms of action. Free and sulfoconjugated catecholamines and serotonin (5-hydroxytryptamine, 5-HT) were measured by high-performance liquid chromatography with electrochemical detection (HPLC-ECD); plasma dopamine (DA)-beta-hydroxylase (DBH) activity was determined by a HPLC technique. When compared with healthy subjects (n = 49), the results in drug addicts (n = 48) revealed: a) Significant increases in plasma DA (free and sulfoconjugated), epinephrine (Epi)- and norepinephrine (NE)-sulfate levels; b) no significant differences in the levels of plasma free NE or Epi, serum and platelet 5-HT. Concerning DBH activity, there was a tendency for an increase. In conclusion, since catecholamines are rapidly inactivated during blood circulation, the measurement of their sulfates may better reflect catecholamine turnover. The differences found may be interpreted as a reflection of the activation of adrenergic neurotransmission, principally as a consequence of catecholamine uptake blockade by cocaine. Finally, in our conditions the abuse of cocaine plus heroin does not significantly interfere with 5-HT uptake by platelets.

[Therapeutic play in the care of hospitalized children: experience of an undergraduate student]

This study describes a phenomenological analysis of a nursing under graduated student's discourse, who used the therapeutic play for caring a hospitalized child. The goal of the study was to understand the meaning of the experience for this student.

Influence of experimental hypercholesterolemia on the monoamine oxidase activity in rabbit arteries

Using a model of experimental atherogenesis in New Zealand rabbits we found a lower noradrenaline level in the aorta than in the femoral artery. The activity of monoamine oxidase was decreased in the femoral artery and increased in the aorta of the cholesterol-fed animals when compared with controls.

[Histocytological correlation in fine needle aspiration biopsy of the thyroid gland]

PURPOSE

To correlate cytological diagnosis with the anatomicopathological ones to assess the accuracy of cytological examination as a diagnostic test.

CASES AND METHOD

The results of 328 cytological diagnoses were compared with the corresponding anatomicopathological results from surgical specimens.

RESULTS

In all thyroid diseases the accuracy of the method was above 95%. Among the more frequent diseases, the sensitivity of the test was 98%, 69%, 81%, 85% and 89%, respectively for nodular colloid goiter, follicular neoplasms, Hashimoto's thyroiditis, papillary carcinoma and Hürthle-cell neoplasia; in all of them the test specificity was at least 89%.

CONCLUSION

Based on these results and owing to its relative simplicity, this study also documents the FNAB usefulness as a diagnostic method for thyroid diseases.

Catecholamine and MHPG plasma levels, platelet MAO activity, and 3H-imipramine binding in heroin and cocaine addicts

This work evaluated in a population of heroin and heroin plus cocaine human addicts: 1. Norepinephrine (NE), epinephrine (Epi) and 3-methoxy-4-hydroxyphenylglycol (MHPG) (the principal metabolite of brain NE) plasma levels; 2. Monoamine oxidase (MAO) activity; and 3. 3H-imipramine specific binding to the amine carrier in platelets. NE plasma levels were significantly lower in the short-term heroin user groups (1-3 and 4-6 yr), a finding not observed in both long-term heroin user ( > 6 yr) and heroin plus cocaine user ( > 6 yr) groups. Epi levels changed in a similar manner, except that a significant increase was noted in heroin plus cocaine abusers. Conversely, dopamine and MHPG plasma levels increased with the duration of heroin use, and even more with cocaine abuse. Platelet MAO activity increased in all groups. Specific 3H-imipramine binding sites showed an increase after 3 yr of heroin abuse and in all heroin plus cocaine addicts. In conclusion, short-term use of heroin decreases NE or Epi release, but with prolonged use, a slow adaptation occurs. In contrast, cocaine inhibits the neuronal Epi uptake, even in a situation of long duration of abuse. Probably the amine levels additionally regulate the amine carrier, resulting in changes that show a different pattern from major depression. These drugs of abuse may also influence directly or indirectly related enzymatic systems.

Acute effects of mercuric chloride on the olfactory epithelium of Trichomycterus brasiliensis

The olfactory organ in fish has a distinct localization, a major biological significance, and an important role in fish behavior. One group of Trichomycterus brasiliensis was exposed to two different concentrations of mercuric chloride (0.05 and 0.1 mg HgCl2 liter-1). The surface of the olfactory epithelium was investigated with scanning electron microscopy. Forty individuals were used in this study. The olfactory epithelia were collected after 4, 12, 24, 48, and 96 hr from contaminated and control aquaria. In the experiment with 0.1 mg HgCl2 liter-1 all individuals died within 24 hr with significant damage to the olfactory epithelium. Type 1 ciliated cells were the most evidently altered. With 0.05 mg HgCl2 liter-1 the initial alterations were considerable, but after 96 hr the epithelial surface recovered its initial appearance compared with the control individuals. This recovery is due to the resistance of this species and to the decrease in the Hg2+ concentration in water. Therefore, the alterations observed in this study reveal that inorganic mercury affects the olfactory organs structurally, with evident interference with normal behavior.

[Pulse wave velocity as initial marker of atherosclerosis]

OBJECTIVE

To evaluate the influence of hypercholesterolaemia on arterial distensibility.

MATERIAL AND METHODS

43 male New Zealand White rabbits, with similar ages and weights, were included in the present study. The animals were divided in two groups: Group A (n = 15) was fed a normal diet; Group B (n = 28) was fed normal diet plus 0.1% cholesterol. at the beginning and after 6 and 9 months, blood samples were obtained for determination of serum cholesterol (total, esterified, LDL) and Triglyceride levels. Pulse wave velocity (PWV) was also evaluated, by mecanography, after 6 and 9 months of the beginning of the experiment. After 6 months (Group A = 4 and Group B = 7) and 9 months (Group A = 6 and Group B = 7) of the experiment, some animals were killed for anatomopathological studies.

RESULTS

Major differences were obtained between the two groups, specially in what concerns to LDL and cholesterol levels (p < 0.001). There was also a remarkable difference in PWV between the two groups (6.078 +/- 0.162/9.002 +/- 0.196 m/s at 6 months and 7.639 +/- 0.590/9.557 +/- 0.543 m/s at 9 months) from the rabbits fed normal or cholesterol diet, respectively. The anatomical lesions were only significant after 9 months. However there was a decrease in aorta internal diameters at thoracic and renal levels at 6 months (34% and 53%) and at 9 months (29% and 33%), without significant changes in their thickness. In the heart, the left ventricle (LV) had a significant thickness increase after 6 months (about 43%).

CONCLUSIONS

These data indicate that even before anatomical lesions had occurred, important functional changes are present, in the arterial wall. Then, the evaluation of the PWV could be a promising non-invasive diagnostic method of early atherosclerosis, with obvious implications concerning its prophylaxis and therapy.

Effect of several electrolyte preservation solutions on the water permeability of isolated cortical collecting ducts perfused in vitro

The extent of nephron injury after long-term preservation is unknown. An experimental protocol was designed to study the effects of 1 and 24 h of cold storage in preservation solution on renal slices of rabbit cortical collecting duct (CCD) isolated and perfused in vitro and evaluated by water hydraulic conductivity. The preservation solutions were Ringer-bicarbonate, Collins, Euro-Collins, and University of Wisconsin (UW). Under these experimental preservation conditions, the following results were observed: after 1 h of preservation, the CCDs obtained from slices incubated in Ringer-bicarbonate, Collins, and Euro-Collins solutions at 4 degrees C presented a high basal hydraulic conductivity compared to the control group and responded well to arginine-vasopressin (AVP) water permeability stimulation. The CCDs derived from renal slices stored for 24 h in Ringer-bicarbonate solution at 4 degrees C showed no function, while those preserved in Collins and Euro-Collins solutions showed a lack of responsiveness to AVP water permeability stimulation. The CCDs preserved in UW solution showed better values than those preserved in the other solutions, although there was a decrease in hydraulic conductivity after 24 h of preservation. These data show that long-term cold preservation with flushed solutions impairs the cortical collecting duct response to AVP.

Bilateral femoral hypoplasia associated with Rokitansky sequence: another example of a mesodermal malformation spectrum?

We report on a woman with bilateral femoral hypoplasia and Rokitansky sequence, malformations that up to now had not been described together. There are no other cases in the family, and no history of prenatal teratogen exposure. This case may be part of a mesodermal malformation spectrum.

Experimental studies on the mechanisms of tiaprofenic acid photosensitization

Red blood cell lysis and histidine degradation, photosensitized by tiaprofenic acid (TIA), were investigated. Photohaemolysis was markedly enhanced in oxygenated solutions, but was also intense in the presence of nitrogen. Photohaemolysis was inhibited by butylated hydroxyanisole and reduced glutathione, but was unaffected by sodium azide, superoxide dismutase and mannitol. The TIA-induced photo-oxidation of histidine was greatly enhanced in the presence of oxygen and almost completely inhibited in solutions bubbled with nitrogen. Sodium azide, butylated hydroxyanisole and reduced glutathione inhibited the photodegradation of histidine. Phototoxicity to histidine was unaffected by mannitol and superoxide dismutase. The overall results suggest that molecular mechanisms involving free radicals and singlet oxygen are responsible for TIA-photosensitized reactions. These two in vitro models (photohaemolysis and histidine degradation) represent different mechanisms of phototoxicity, but complement one another in the investigation of potential phototoxic substances.

Changes in platelet membrane fluidity of migraine patients

Platelet membrane fluidity was measured in migraine patients, with and without aura, using the fluorescent probe TMA-DPH (1-[4-(trimethylammonium) phenyl]-6-hexa-1,3,5- triene). Polarization values for TMA-DPH were significantly higher in the platelet membranes of migraine patients (with or without aura) than in those of healthy subjects. These findings signify decreased membrane fluidity and may explain some modifications in receptors, carriers or enzymes described in platelets of migraine patients.

Photosensitivity to piroxicam: absence of cross-reaction with tenoxicam

We studied 2 groups of patients. One group of 10 patients had a photosensitive eruption to piroxicam. Another group of 24 patients had positive patch test reactions to thimerosal and thiosalicylic acid and had never taken piroxicam or tenoxicam. Patients were patch tested with thimerosal 0.1% pet., thiosalicylic acid 0.1% pet., salicylic acid 2.0% pet., piroxicam 1 and 5% pet. and tenoxicam 1 and 5% pet. Photopatch tests were also performed with piroxicam and tenoxicam. All 10 patients with photosensitivity to piroxicam had positive patch tests to thimerosal and thiosalicylic acid and 9 of them had positive photopatch tests to piroxicam. 20 out of 24 patients with positive patch tests to thiosalicylic acid also had positive photopatch tests to piroxicam. All the patients tested with salicyclic acid were negative. Out of the 29 patients with positive photopatch tests to piroxicam, none reacted to tenoxicam. In countries with a high incidence of contact sensitivity to thimerosal/thiosalicylic acid, the use of piroxicam should be avoided and replaced by tenoxicam, a drug without reported photosensitivity.

Tiaprofenic acid-induced photohemolysis in vitro is inhibited by nimesulide

The effect of nimesulide on red blood cell (RBC) lysis photosensitized by tiaprofenic acid was investigated. The tiaprofenic acid-induced photohemolysis rate was enhanced by exposure to oxygen but lysis was also observed under anaerobic conditions. Photohemolysis was decreased by reduced glutathione (GSH) and reduced even more by butylated hydroxyanisole (BHA); sodium azide, superoxide dismutase and mannitol did not show a significant effect. Nimesulide did not cause any RBC lysis and inhibited this action of tiaprofenic acid by 20-30%, depending on the concentration of nimesulide and the intensity of ultraviolet A light. The protective effect of GSH, but not of BHA, was increased by nimesulide. Our findings suggest that free radicals are generated in this in vitro model of phototoxicity and are involved in the photoaggression to the red blood cell membrane, this effect being partially inhibited by nimesulide.

[The effect of the use of therapeutic play by the pediatric nurse on the behavior of recently hospitalized children]

This work describes the realization and the results of one experimental research accomplished with children from 3 to 5 years of age, recently-hospitalized using the therapeutic-play. The results showed that it helped children behave more according to what is expected of this 3-5 age group, as well as show signs that they had adapted or presented ego strength.

Pharmacological characterization of the postsynaptic serotonergic receptor in the human uterine artery

Serotonergic receptors are involved in many vascular functions, but only a few studies have been made in human vessels. Thus, this study aimed to characterize these receptors in the human uterine artery without endothelium. The pD2 value of serotonin (5-HT) was 5.96, but the intrinsic activity was 59% of that of noradrenaline. Spiperone and ketanserin shifted the concentration-response curves of 5-HT to the right (pA2 = 8.56 and 9.76; slopes = 0.98 and 0.83, respectively). Propranolol, yohimbine, prazosin and atropine did not significantly shift the concentration-response curves to 5-HT. Phentolamine inhibited the 5-HT response (pA2 = 6.69), and previous treatment of the vascular strips with 6-hydroxydopamine only partially reduced such an effect. The results demonstrate the existence, in the human uterine artery, of 5-HT2 receptors which are blocked by high concentrations of phentolamine. In this tissue, 5-HT does not release noradrenaline from perivascular nerves.

Migraine, serum serotonin and platelet 5-HT2 receptors

In spite of recent theories about the aetiopathogenesis of migraine, serotonin continues to play a central role, explaining the efficacy of almost all migraine prophylactic drugs. In migraineurs with and without aura we measured (by HPLC-EC) the serum serotonin (5-HT) and 5-hydroxyindoleacetic acid (5-HIAA) levels between as well as during headache attacks. Between attacks of migraine with aura and at the beginning of attacks of both types of migraine the serum 5-HT and 5-HIAA concentration was significantly increased. These results were corroborated by 3H-spiperone binding to platelet membranes: in migraineurs with aura in the attack-free interval, there was a significant decrease in its Bmax, which suggests down-regulation of 5-HT2 receptors. In conclusion, we have verified that migraine with aura differs biochemically from migraine without aura.

Mechanism of action of doxepin in the treatment of chronic urticaria

The present study examined 15 patients previously resistant to conventional antihistamines, in which doxepin at doses in the range of 50-75 mg/day was shown to be effective in treatment of chronic urticaria and without significant adverse side effects. However, some controversy remains about its mechanism of action in this particular disease. The aim of the present study was to examine the muscarinic, H1 and H2 blocking activity of doxepin. The following methods were used: a) gastric acid hypersecretion induced by histamine and carbachol in the pylorus-ligated rat preparation; b) contractile dose-response curves to histamine and carbachol in the guinea pig ileum; c) dimaprit-stimulated guinea pig atrium in vitro. pA2 values were determined for atropine, mepyramine, cimetidine and doxepin. As regards histamine, doxepin (50 mg/kg, po) increased gastric pH and decreased secretion volume, gastric acid concentration and total acid output; with carbachol, doxepin weakly antagonized those values. In the ileum, doxepin competitively antagonized carbachol (pA2 = 7.08) and histamine (pA2 = 9.72); pA2 values for atropine and mepyramine against carbachol and histamine were 9.11 and 8.82, respectively. In the atria, the dose-response curve to dimaprit was also competitively displaced by cimetidine (pA2 = 6.69) and doxepin (pA2 = 6.00). Doxepin displayed a very high affinity for H1 histamine receptor, being 8-fold more potent than mepyramine. Doxepin showed significant H2 blocking activity which was 5 times less potent than that of cimetidine. Doxepin competitively antagonized carbachol in the guinea pig ileum, and was 107 times less potent than atropine. The combined H1, H2 and muscarinic blocking activities of doxepin may contribute towards explaining its clinical efficacy in the treatment of chronic urticaria.

Piroxicam-induced photosensitivity

During the last 3 years, 9 patients with a photosensitive eruption related to piroxicam therapy were seen. In all but one, it occurred within 4 days of first exposure to the drug. 7 patients required systemic corticosteroids, and 2 hospitalization. Clinical, histological and provocation studies were not conclusive in classifying the eruption as photoallergic or phototoxic. Experimental studies including photohaemolysis, Bacillus subtilis culture and nuclear magnetic resonance showed: (i) in irradiated piroxicam solutions, there was more haemolysis; (ii) in irradiated Petri dishes, piroxicam solutions showed greater inhibition of growth of B. subtilis; (iii) Piroxicam's NMR spectrum is not modified after irradiation. The results provide evidence of piroxicam phototoxic potential.

Consumer payment patterns for primary health care services in low-income communities of Rio de Janeiro: implications for designing service financing schemes

Primary health care (PHC) services are now recognized as a mainstay of development in low-income regions of the world. Yet, in many of these areas, economic conditions that include a burgeoning international debt, precipitous drops in the prices of raw materials, expanding population bases, and faltering currency rates, make the effective financing of PHC services an issue requiring the most immediate attention. A potentially valuable source of assistance in such endeavors is data on consumers' payment patterns for PHC services, and on socioeconomic conditions within their communities. The Centro de Pesquisas de Assistência Integrada à Mulher e à Criança (CPAIMC), the principal private source of PHC in Rio de Janeiro, has collected these type of data for nine low-income communities (LICs) within the Greater Rio de Janeiro Metropolitan Region. The current paper interfaces these data with previously developed solutions to address the problem of financing PHC services within the nine LICs. The solutions were recommended by a methodology developed and implemented by two of the authors. Results indicate that the consumer payment pattern and socioeconomic data support the methodology's recommendations and, more importantly, may be used to improve the effectiveness of those recommendations. Examples are provided and implications discussed.

Pharmacological characterization of the postsynaptic alpha-adrenoceptors in human uterine artery

Prazosin and yohimbine were used to differentiate postjunctional alpha-adrenoceptors in the human uterine artery in-vitro. Two postjunctional alpha-adrenoceptor subtypes were distinguished by the affinities of the receptor for yohimbine and prazosin. The pA2 for prazosin was 8.91 against phenylephrine with a slope not significantly different from unity (0.91), and the pA2 for yohimbine was 7.25 against naphazoline and 8.70 against clonidine, with slopes not significantly different from unity (1.11 and 1.18, respectively). Yohimbine was not very active against phenylephrine, while prazosin was very active against the mixed and selective alpha 2-adrenoceptor agonist noradrenaline and clonidine; the intercepts of the Schild plot were 8.80 and 8.82 but with slopes significantly less than unity (0.77 and 0.67, respectively). Prazosin competitively antagonized phenylephrine at the alpha 1-adrenoceptor, whereas yohimbine competitively antagonized naphazoline and clonidine at the alpha 2-adrenoceptor. It is concluded that both alpha 1- and alpha 2-adrenoceptors are present in the human uterine artery.

Renal tubular sodium reabsorption during the recovery from the oliguric phase of acute nephritis

The urinary excretion of sodium, calcium, phosphorus and the reabsorption of solute free-water, were studied in seven water-restricted patients with post-streptococcal acute glomerulonephritis. During the recovery from the initial salt-retaining phase, there was a progressive increase in the urinary excretion of sodium, phosphorus and calcium either in absolute values or when expressed as their tubular rejection fractions. A progressive increase in free-water reabsorption as percentage of creatinine clearance was also demonstrated. The data suggest that in this phase of the disease there occurs a non specific supression of proximal tubular activity.