Spatial distribution and developmental appearance of postjunctional P2X(1) receptors on smooth muscle cells of the mouse vas deferens

P2X(1)-type purinoceptors, have been shown to mediate fast transmission between sympathetic varicosities and smooth muscle cells in the mouse vas deferens but the spatial organization of these receptors on the smooth muscle cells remains inconclusive. Voltage clamp techniques were used to estimate the amplitudes of spontaneous excitatory junction currents (SEJCs) in cells of the vas deferens longitudinal smooth muscle layer. These currents involved the activation of about 6% of the P2X-type channels present on the cell, as compared to whole cell currents produced when isolated smooth muscle cells were exposed to maximal concentrations of either ATP or alpha,beta -MeATP. Immunofluorescence staining of the vas deferens with antibodies against P2X(1) receptor showed a diffuse, grainy distribution over the entire membrane of each smooth muscle cell. Anti-P2X(1) staining was not markedly clustered beneath anti-SV2-stained sympathetic varicosities. Similar results were obtained for cells in the urinary bladder. During development, P2X(1) mRNA was detected as early as embryonic day 15 (E15). Increasing intensities of diffuse immunostaining for P2X(1) were observed in the walls of the bladder, tail artery, and aorta from E15 until 6 weeks postnatal. The vas deferens showed increasing intensities of diffuse staining of its smooth muscle layers between 2 and 6 weeks postnatal, consistent with the time-course of development of fast purinergic transmission described previously. Together, the results suggest that the response of smooth muscle of the vas deferens to ATP released from sympathetic varicosities relies on rapidly desensitizing P2X(1) receptors, distributed diffusely across the smooth muscle cell surface. Synapse 42:1-11, 2001. (C) 2001 Wiley-Liss, Inc.

Novel MUCI splice variants are expressed in cervical carcinoma

Objectives. The MUC1 antigen can be used to identify epithelial cells from the background of hemopoietic cells. The present investigation describes patterns of overexpression of two novel MUC1 splice variants in human cervical carcinoma cell lines. Methods. RT-PCR was carried out to determine MUC1 splice variants in the cervical cancer cell lines C-4 II, C-33A, DoTc 2 4510, C-4 I, SiHa, HT3, Hs 636 T (C4-I), and HeLa. Results. The novel MUC1 splice variant D was expressed in all cell lines and the novel MUC1 splice variant C was expressed in all cell lines but C-33A. Variants A and B were expressed in all (variant A) and all but one (variant B) cell line. MUC1/REP was expressed in all cell lines and MUC1/SEC was positive in all but two cell lines (C-33 A, DoTc 2 4510). All but one cell line (C-33A) expressed MUC1/X and MUC1/Y, and two cell lines (C-33 A, DoTc 2 4510) did not express MUC1/Z, respectively. MUC1 variants A, D, and REP could be demonstrated consistently among all eight cervical carcinoma cell lines we have examined. Conclusions. The present study describes the feasibility of detecting a large number of MUC1 variants, including MUC1 variants C and D which are described for cervical carcinoma cells for the first time. Further studies will examine the presence of MUC1 splice variants' expression in human cervical carcinoma tissue.

Axonal regeneration of retinal ganglion cells after optic nerve pre-lesions and attachment of normal or pre-degenerated peripheral nerve grafts

Axonal regeneration of retinal ganglion cells (RGCs) into a normal or pre-degenerated peripheral nerve graft after an optic nerve pre-lesion was investigated. A pre-lesion performed 1-2 weeks before a second lesion has been shown to enhance axonal regeneration in peripheral nerves (PN) but not in optic nerves (ON) in mammals. The lack of such a beneficial pre-lesion effect may be due to the long delay (1-6 weeks) between the two lesions since RGCs and their axons degenerate rapidly 1-2 weeks following axotomy in adult rodents. The present study examined the effects of the proximal and distal ON pre-lesions with a shortened delay (0-8 days) on axonal regeneration of RGCs through a normal or pre-degenerated PN graft. The ON of adult hamsters was transected intraorbitallv at 2 mm. (proximal lesion) or intracranially at 7 mm (distal lesion) from the optic disc. The pre-lesioned ON was re-transected at 0.5 mm from the disc after 0, 1, 2, 4, or 8 days and a normal or a pre-degenerated PN graft was attached onto the ocular stump. The number of RGCs regenerating their injured axons into the PN graft was estimated by retrograde labeling with FluoroGold 4 weeks after grafting. The number of regenerating RGCs decreased significantly when the delay-time increased in animals with both the ON pre-lesions (proximal or distal) compared to control animals without an ON pre-lesion. The proximal ON pre-lesion significantly reduced the number of regenerating RGCs after a delay of 8 days in comparison with the distal lesion. However, this adverse effect can be overcome, to some degree, by a pre-degenerated PN graft applied 2, 4, or 8 days after the distal ON pre-lesion enhanced more RGCs to regenerate than the normal PN graft. Thus, in order to obtain the highest number of regenerating RGCs, a pre-degenerated PN should be grafted immediately after an ON lesion.

Effects of additional sequences directly downstream from the AUG on the expression of GFP gene

We have studied the expression of the green fluorescent protein (GFP) gene to gain more understanding of the effects of additional nucleotide triplets (codons) downstream from the initiation codon on the translation of the GFP mRNA in CHO and Cos1 cells. A leader sequence of six consecutive identical codons (GUG, CUC, AGU or UCA) was introduced into a humanized GFP (hm gfp) gene downstream from the AUG to produce four GFP gene variants. Northern blot and RT-PCR analysis indicated that mRNA transcription from the GFP gene was not significantly affected by any of the additional sequences. However, immunoblotting and FACS analysis revealed that AGU and UCA GFP variants produced GFP at a mean level per cell 3.5-fold higher than the other two GFP variants and the hm gfp gene. [35S]-Methionine labeling and immunoprecipitation demonstrate that GFP synthesis was very active in UCA variant transfected-cells, but not in GUG variant and hm gfp transfected-cells. Moreover, proteasome inhibitor MG-132 treatment indicated that the GFPs encoded by each of the GFP variants and the hm gfp were equally stable, and this together with the comparable mRNA levels observed for each construct suggested that the different steady-state GFP concentrations observed reflected different translation efficiencies of the various GFP genes. In addition, the CUC GFP variant, when transiently transfected into CHO or COS-1 cells, did not produce any GFP expressing cells (fully green cells), and the GUG variant produced GFP expressing cells less than 10%, while AGU and UCA GFP variants up to 30–35% in a time course study from 8 to 36 h posttransfection. Analysis of the potential secondary structure of the GFP variant mRNAs especially in the translation initiation region suggested that the secondary structure of the GFP mRNAs was unlikely to explain the different translation efficiencies of the GFP variants. The present findings indicate that a change of the initiation context of the GFP gene by addition of extra coding sequence can alter the translation efficiency of GFP mRNA, providing a means of more efficient expression of GFP in eukaryotic cells.

Effects of herbicides diuron and atrazine on corals of the Great Barrier Reef, Australia

In response to recent reports of contamination of the nearshore marine environment along the Queensland coast by herbicides (including areas inside the Great Barrier Reef Marine Park), an ecotoxicological assessment was conducted of the impact of the herbicides diuron and atrazine on scleractinian corals. Pulse-amplitude modulated (PAM) chlorophyll fluorescence techniques were used to assess the herbicide effects on the symbiotic dinoflagellates within the tissues (in hospite) of 4 species of coral (Acropora formosa, Montipora digitata, Porites cylindrica, Seriatopora hystrix) in static toxicity tests, and in freshly isolated symbiotic dinoflagellates from Stylophora pistillata. Using change in the effective quantum yield (DeltaF/F-m') as an effect criterion, diuron (no observable effect concentration, NOEC = 0.3 mug 1(-1); lowest observable effect concentration, LOEC = 1 mug 1(-1); median effective concentration, EC50 4 to 6 mug 1(-1)) was found to be more toxic than atrazine (NOEC = 1 mug 1(-1), LOEC = 3 mug 1(-1), EC50 40 to 90 mug 1(-1)) in short-term (10 h) toxicity tests. In the tests with isolated algae, significant reductions in DeltaF/F-m' were recorded as low as 0.25 mug 1(-1) diuron (LOEC, EC50 = 5 mug 1(-1)). Time-course experiments indicated that the effects of diuron were rapid and reversible. At 10 mug 1(-1) diuron, DeltaF/F-m' was reduced by 25% in 20 to 30 min, and by 50% in 60 to 90 min. Recovery of DeltaF/F-m' in corals exposed to 10 mug 1(-1) diuron and then transferred to running seawater was slower, returning to within 10% of control values inside 1 to 7 h. The effect of a reduction in salinity (35 to 27%) on diuron toxicity (at 1 and 3 mug 1(-1) diuron) was tested to examine the potential consequences of contaminated coastal flood plumes inundating inshore reefs. DeltaF/F-m' was reduced in the diuron-exposed corals, but there was no significant interaction between diuron and reduced salinity seawater within the 10 h duration of the test. Exposure to higher (100 and 1000 mug 1(-1)) diuron concentrations for 96 h caused a reduction in DeltaF/F-m' the ratio variable to maximal fluorescence (F,1F.), significant loss of symbiotic dinoflagellates and pronounced tissue retraction, causing the corals to pale or bleach. The significance of the results in relation to diuron contamination of the coastal marine environment from terrestrial sources (mainly agricultural) and marine sources (antifouling paints) are discussed.

Caracterização do papel da adrenalina na maturação dos adrenorreceptores B2

As respostas pós-juncionais mediadas por adrenorreceptores β2 (ARβ2), responsáveis pelo relaxamento do músculo liso, na veia safena do cão, estão ausentes à nascença. Pelo contrário, no rato recém-nascido já se verifica a estimulação da adenilil ciclase pela activação dos ARβ2. Não existem ainda estudos no coelho recém-nascido. O principal objectivo deste trabalho é avaliar as respostas pós-juncionais mediadas pelos ARβ2 em coelhos recém-nascidos e jovens e relacionar essas respostas com a adrenalina produzida nas glândulas supra-renais. Traçaram-se curvas de dose-resposta à isoprenalina (agonista β) utilizando-se anéis de aorta montados em banho de órgãos isolados ligado a um transdutor de força isométrica. As catecolaminas das supra-renais foram quantificadas por RP-HPLC-ED. Em aortas pré-contraídas com fenilefrina (agonista α1), a isoprenalina causou relaxamento total apenas em coelhos recém-nascidos (n=10). O relaxamento máximo nos coelhos jovens foi de 21±4% (n=23). A potência da isoprenalina foi maior nos recém-nascidos (EC50=1.15×10-8±7.2×10-10 M, n=10) do que nos coelhos jovens (EC50=1.29×10-7 ±4.7×10-9 M, n=23). O relaxamento máximo com isoprenalina, em aortas pré-contraídas com prostaglandina F2α (PGF2α), no grupo de coelhos recém-nascidos foi de 95±3.6% (n=16). O relaxamento máximo nos coelhos jovens foi de 43.7±8.6% (n=9). Na pré-contracção com PGF2α a potência da isoprenalina registou-se maior nos recémnascidos (EC50=9.59×10-9±4.0×10-10 M, n=16) do que nos coelhos jovens (EC50=2.13×10- 8±3.8×10-9 M, n=9), estando concordante com os resultados da pré-contracção com fenilefrina. Nas supra-renais dos recém-nascidos, o conteúdo de noradrenalina foi de 586±128 nmol/mg e da adrenalina foi de 1915±356 nmol/mg (n=4) e nos coelhos jovens foi de 112±12 nmol/mg e de 3644±403 nmol/mg (n=6), respectivamente. As respostas mediadas por ARβ2 no coelho desenvolvem-se mais cedo do que no cão, pois já estão presentes no nascimento. Tal como no rato, no coelho a adrenalina é já a catecolamina em maior quantidade à nascença, enquanto no cão é vestigial. Há uma relação temporal entre a síntese da adrenalina, a única catecolamina biogénica com alta afinidade para os ARβ2 e a maturação das respostas pós-juncionais mediadas por esses receptores. Um protocolo para experiências futuras destinadas a testar esta hipótese, com base no knockdown da Feniletanolamina-N-metiltransferase por RNAi foi elaborado e incluído neste documento.

The effects of air pollution on cardiovascular diseases: lag structures

OBJECTIVE: To assess the lag structure between air pollution exposure and elderly cardiovascular diseases hospital admissions, by gender. METHODS: Health data of people aged 64 years or older was stratified by gender in São Paulo city, Southeastern Brazil, from 1996 to 2001. Daily levels of air pollutants (CO, PM10, O3, NO2, and SO2) , minimum temperature, and relative humidity were also analyzed. It were fitted generalized additive Poisson regressions and used constrained distributed lag models adjusted for long time trend, weekdays, weather and holidays to assess the lagged effects of air pollutants on hospital admissions up to 20 days after exposure. RESULTS: Interquartile range increases in PM10 (26.21 mug/m³) and SO2 (10.73 mug/m³) were associated with 3.17% (95% CI: 2.09-4.25) increase in congestive heart failure and 0.89% (95% CI: 0.18-1.61) increase in total cardiovascular diseases at lag 0, respectively. Effects were higher among female group for most of the analyzed outcomes. Effects of air pollutants for different outcomes and gender groups were predominately acute and some "harvesting" were found. CONLUSIONS: The results show that cardiovascular diseases in São Paulo are strongly affected by air pollution.

Familial amyloid polyneuropathy (FAP): clinical features, pathophysiology and treatment

In the literature, concepts of “polyneuropathy”, “peripheral neuropathy” and “neuropathy” are often mistakenly used as synonyms. Polyneuropathy is a specific term that refers to a relatively homogenous process that affects multiple peripheral nerves. Most of these tend to present as symmetric polyneuropathies that first manifest in the distal portions of the affected nerves. Many of these distal symmetric polyneuropathies are due to toxic-metabolic causes such as alcohol abuse and diabetes mellitus. Other distal symmetric polyneuropathies may result from an overproduction of substances that result in nerve pathology such as is observed in anti-MAG neuropathy and monoclonal gammopathy of undetermined significance. Other “overproduction” disorders are hereditary such as noted in the Portuguese type of familial amyloid polyneuropathy (FAP). FAP is a manifestation of a group of hereditary amyloidoses; an autosomal dominant, multisystemic disorder wherein the mutant amyloid precursor, transthyretin, is produced in excess primarily by the liver. The liver accounts for approximately 98% of all transthyretin production. FAP is confirmed by detecting a transthyretin variant with a methionine for valine substitution at position 30 [TTR (Met30)]. Familial Amyloidotic Polyneuropathy (FAP) – Portuguese type was first described by a Portuguese neurologist, Corino de Andrade in 1939 and published in 1951. Most persons with this disorder are descended from Portuguese sailors who sired offspring in various locations, primarily in Sweden, Japan and Mallorca. Their descendants emigrated worldwide such that this disorder has been reported in other countries as well. More than 2000 symptomatic cases have been reported in Portugal. FAP progresses rapidly with an average time course from symptom onset to multi-organ involvement and death between ten and twenty years. Treatments directed at removing this aberrant protein such as plasmapheresis and immunoadsorption proved to be unsuccessful. Liver transplantation has been the only effective solution as evidenced by almost 2000 liver transplants performed worldwide. A therapy for FAP with a novel agent, “Tafamidis” has shown some promise in ongoing phase III clinical trials. It is well recognized that regular physical activity of moderate intensity has a positive effect on physical fitness as gauged by body composition, aerobic capacity, muscular strength and endurance and flexibility. Physical fitness has been reported to result in the reduction of symptoms and lesser impairment when performing activities of daily living. Exercise has been advocated as part of a comprehensive approach to the treatment of chronic diseases. Therefore, this chapter concludes with a discussion of the role of exercise training on FAP.

Bullying escolar – Intervenientes, ações e sentimentos associados: um estudo com alunos do 2º e 3º ciclos da região do Algarve

Introdução – O bullying pode ser definido como atitudes agressivas, intencionais e repetidas durante um período de tempo. Diversos estudos verificaram a prevalência de bullying entre estudantes de vários países e demonstraram que este é um problema internacional e que pelo menos um em cada dez estudantes está envolvido numa situação de bullying. Objetivos – Caracterizar as situações de bullying no ambiente escolar, o papel do estudante, os sentimentos associados a essas ações e identificar as características do agressor. Métodos – A amostra foi constituída por 519 alunos matriculados em duas escolas da região sul de Portugal que preencheram um questionário anónimo sobre uma situação de bullying que vivenciaram, descrevendo o papel do aluno e o que sentiram nesta situação. Resultados – Os resultados revelaram que em 61,7% dos casos se tratou de agressão física e 29,7% de agressão verbal. Desempenharam o papel de agressores 12,7% dos alunos, 21,8% foram vítimas e 63,6% foram testemunhas desta situação. 10,6% dos alunos relataram sentir bem, 11% mostraram indiferença e 78,4% dos alunos sentiram‑se mal com a situação de bullying. Verificou‑se que, com o avanço da idade, o estudante aumentava em 1,5 vezes a probabilidade de desempenhar o papel de agressor e os rapazes apresentavam 5,2 vezes mais probabilidades de vir a ser agressor numa situação de bullying. Conclusão – O presente estudo verificou que a maioria dos alunos participou de uma situação de bullying escolar como testemunha, sendo os casos mais comuns de agressão física. A maioria dos alunos sentiu‑se mal com essa situação. Os rapazes e os alunos com mais idade tiveram mais probabilidade de vir a desempenhar o papel de agressor numa situação de bullying.

Principal components and generalized linear modeling in the correlation between hospital admissions and air pollution

OBJECTIVE To analyze the association between concentrations of air pollutants and admissions for respiratory causes in children. METHODS Ecological time series study. Daily figures for hospital admissions of children aged < 6, and daily concentrations of air pollutants (PM10, SO2, NO2, O3 and CO) were analyzed in the Região da Grande Vitória, ES, Southeastern Brazil, from January 2005 to December 2010. For statistical analysis, two techniques were combined: Poisson regression with generalized additive models and principal model component analysis. Those analysis techniques complemented each other and provided more significant estimates in the estimation of relative risk. The models were adjusted for temporal trend, seasonality, day of the week, meteorological factors and autocorrelation. In the final adjustment of the model, it was necessary to include models of the Autoregressive Moving Average Models (p, q) type in the residuals in order to eliminate the autocorrelation structures present in the components. RESULTS For every 10:49 μg/m3 increase (interquartile range) in levels of the pollutant PM10 there was a 3.0% increase in the relative risk estimated using the generalized additive model analysis of main components-seasonal autoregressive – while in the usual generalized additive model, the estimate was 2.0%. CONCLUSIONS Compared to the usual generalized additive model, in general, the proposed aspect of generalized additive model − principal component analysis, showed better results in estimating relative risk and quality of fit.

Disparities in cervical and breast cancer mortality in Brazil

OBJECTIVE To analyze cervical and breast cancer mortality in Brazil according to socioeconomic and welfare indicators. METHODS Data on breast and cervical cancer mortality covering a 30-year period (1980-2010) were analyzed. The data were obtained from the National Mortality Database, population data from the Brazilian Institute of Geography and Statistics database, and socioeconomic and welfare information from the Institute of Applied Economic Research. Moving averages were calculated, disaggregated by capital city and municipality. The annual percent change in mortality rates was estimated by segmented linear regression using the joinpoint method. Pearson’s correlation coefficients were conducted between average mortality rate at the end of the three-year period and selected indicators in the state capital and each Brazilian state. RESULTS There was a decline in cervical cancer mortality rates throughout the period studied, except in municipalities outside of the capitals in the North and Northeast. There was a decrease in breast cancer mortality in the capitals from the end of the 1990s onwards. Favorable socioeconomic indicators were inversely correlated with cervical cancer mortality. A strong direct correlation was found with favorable indicators and an inverse correlation with fertility rate and breast cancer mortality in inner cities. CONCLUSIONS There is an ongoing dynamic process of increased risk of cervical and breast cancer and attenuation of mortality because of increased, albeit unequal, access to and provision of screening, diagnosis and treatment. 

Isolated and synergistic effects of PM10 and average temperature on cardiovascular and respiratory mortality

OBJECTIVE To analyze the effect of air pollution and temperature on mortality due to cardiovascular and respiratory diseases. METHODS We evaluated the isolated and synergistic effects of temperature and particulate matter with aerodynamic diameter < 10 µm (PM10) on the mortality of individuals > 40 years old due to cardiovascular disease and that of individuals > 60 years old due to respiratory diseases in Sao Paulo, SP, Southeastern Brazil, between 1998 and 2008. Three methodologies were used to evaluate the isolated association: time-series analysis using Poisson regression model, bidirectional case-crossover analysis matched by period, and case-crossover analysis matched by the confounding factor, i.e., average temperature or pollutant concentration. The graphical representation of the response surface, generated by the interaction term between these factors added to the Poisson regression model, was interpreted to evaluate the synergistic effect of the risk factors. RESULTS No differences were observed between the results of the case-crossover and time-series analyses. The percentage change in the relative risk of cardiovascular and respiratory mortality was 0.85% (0.45;1.25) and 1.60% (0.74;2.46), respectively, due to an increase of 10 μg/m3 in the PM10 concentration. The pattern of correlation of the temperature with cardiovascular mortality was U-shaped and that with respiratory mortality was J-shaped, indicating an increased relative risk at high temperatures. The values for the interaction term indicated a higher relative risk for cardiovascular and respiratory mortalities at low temperatures and high temperatures, respectively, when the pollution levels reached approximately 60 μg/m3. CONCLUSIONS The positive association standardized in the Poisson regression model for pollutant concentration is not confounded by temperature, and the effect of temperature is not confounded by the pollutant levels in the time-series analysis. The simultaneous exposure to different levels of environmental factors can create synergistic effects that are as disturbing as those caused by extreme concentrations.

Air pollution and its impacts on health in Vitoria, Espirito Santo, Brazil

ABSTRACT OBJECTIVE To analyze the impact of air pollution on respiratory and cardiovascular morbidity of children and adults in the city of Vitoria, state of Espirito Santo. METHODS A study was carried out using time-series models via Poisson regression from hospitalization and pollutant data in Vitoria, ES, Southeastern Brazil, from 2001 to 2006. Fine particulate matter (PM10), sulfur dioxide (SO2), and ozone (O3) were tested as independent variables in simple and cumulative lags of up to five days. Temperature, humidity and variables indicating weekdays and city holidays were added as control variables in the models. RESULTS For each increment of 10 µg/m3 of the pollutants PM10, SO2, and O3, the percentage of relative risk (%RR) for hospitalizations due to total respiratory diseases increased 9.67 (95%CI 11.84-7.54), 6.98 (95%CI 9.98-4.17) and 1.93 (95%CI 2.95-0.93), respectively. We found %RR = 6.60 (95%CI 9.53-3.75), %RR = 5.19 (95%CI 9.01-1.5), and %RR = 3.68 (95%CI 5.07-2.31) for respiratory diseases in children under the age of five years for PM10, SO2, and O3, respectively. Cardiovascular diseases showed a significant relationship with O3, with %RR = 2.11 (95%CI 3.18-1.06). CONCLUSIONS Respiratory diseases presented a stronger and more consistent relationship with the pollutants researched in Vitoria. A better dose-response relationship was observed when using cumulative lags in polynomial distributed lag models.

Hospitalization due to drug use did not change after a decade of the Psychiatric Reform

ABSTRACT OBJECTIVE To investigate whether the psychiatric hospitalization rates due to use of psychoactive substances and average time of hospitalization suffered any changes after the first decade of effective implementation of the psychiatric reform in Brazil. METHODS This article examines the evolution of hospitalizations due to disorders arising from the use of alcohol or other substances in the state of Santa Catarina, Southern Brazil, from 2000 to 2012. This is an ecological, time-series study, which uses data from admissions obtained by the Informatics Service of the Brazilian Unified Health System. Hospitalization rates by 100,000 inhabitants and average time of occupancy of beds were estimated. Coefficients of variation of these rates were estimated by Poisson Regression. RESULTS The total and male hospitalization rates did not vary (p = 0.056 and p = 0.244, respectively). We observed an increase of 3.0% for the female sex (p = 0.049). We did not observe any significant variation for occupancy time of beds. CONCLUSIONS The deployment of services triggered by the Brazilian psychiatric reform was not accompanied by a reduction of hospitalization rates or mean occupancy time of hospitalized patients during this first decade of implementation of the reform.

Difficulties in access and estimates of public beds in intensive care units in the state of Rio de Janeiro

ABSTRACT OBJECTIVE To estimate the required number of public beds for adults in intensive care units in the state of Rio de Janeiro to meet the existing demand and compare results with recommendations by the Brazilian Ministry of Health. METHODS The study uses a hybrid model combining time series and queuing theory to predict the demand and estimate the number of required beds. Four patient flow scenarios were considered according to bed requests, percentage of abandonments and average length of stay in intensive care unit beds. The results were plotted against Ministry of Health parameters. Data were obtained from the State Regulation Center from 2010 to 2011. RESULTS There were 33,101 medical requests for 268 regulated intensive care unit beds in Rio de Janeiro. With an average length of stay in regulated ICUs of 11.3 days, there would be a need for 595 active beds to ensure system stability and 628 beds to ensure a maximum waiting time of six hours. Deducting current abandonment rates due to clinical improvement (25.8%), these figures fall to 441 and 417. With an average length of stay of 6.5 days, the number of required beds would be 342 and 366, respectively; deducting abandonment rates, 254 and 275. The Brazilian Ministry of Health establishes a parameter of 118 to 353 beds. Although the number of regulated beds is within the recommended range, an increase in beds of 122.0% is required to guarantee system stability and of 134.0% for a maximum waiting time of six hours. CONCLUSIONS Adequate bed estimation must consider reasons for limited timely access and patient flow management in a scenario that associates prioritization of requests with the lowest average length of stay.