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1.
Ambio ; 52(1): 195-209, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-36001251

RESUMO

Canals and canalized rivers form a major part of surface water systems in European delta cities and societal ambitions to use these waters increase. This is the first assessment of how suitability of these waters can improve for three important uses: transportation, thermal energy extraction (TEE) and recreation. We assess suitability with Suitability Indices (SIs) and identify which alterations in the water system are needed to improve SI scores in Amsterdam, The Netherlands, and Ghent, Belgium. The results show spatial variability in suitability scores. Current suitability for transportation is low (SI score = 1) to excellent (SI score = 4), for TEE fair (SI score = 2) to excellent (SI score = 4), and suitability for recreation is low (SI score = 1). Suitability could improve by enlarging specific waterway dimensions, increasing discharge and clarity, and by enhancing microbiological water quality. The same methodology can be applied to optimize designs for new water bodies and for more water uses.


Assuntos
Monitoramento Ambiental , Rios , Rios/microbiologia , Cidades , Monitoramento Ambiental/métodos , Recreação , Qualidade da Água
2.
Clin Exp Allergy ; 41(2): 232-42, 2011 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-21121978

RESUMO

BACKGROUND: Allergic diseases are increasing world-wide, and according to the hygiene hypothesis may be related to a decreased exposure to environmental bacteria. Probiotic bacteria are recognized for their immunomodulating properties, and may benefit allergy patients. In vitro studies reveal immunomodulatory effects that are strain dependent. Differential immunomodulatory in vitro capacities cannot be extrapolated directly to in vivo efficacy. Thus, in vitro screening should preferably be followed by a comparative analysis of the selected immunomodulatory strains in an in vivo setting. OBJECTIVE: We selected five Lactobacillus strains on their IL-10-inducing capacity, and evaluated the immunomodulatory properties in birch-pollen-allergic subjects outside the hayfever season, with a reduction of IL-13 as the primary outcome. METHODS: A double-blind, placebo-controlled parallel study was performed in which 62 subjects with a proven birch-pollen allergy consumed one of five different probiotic yoghurts containing four Lactobacillus plantarum strains and one Lactobacillus casei strain or a placebo yoghurt. Blood samples were collected at the start and after 4 weeks. Several immune parameters were determined in serum and peripheral blood mononuclear cell cultures (PBMC) derived from these subjects. Results A decrease in birch-pollen-specific IgE was found for four probiotic strains. L. casei Shirota reduced the number of CD16(+) /CD56(+) cells in peripheral blood mononuclear cells. For strain L. plantarum CBS125632, the decrease in IgE coincided with significant decreases in IL-5 and IL-13 production by αCD3/αCD28-stimulated PBMC cultures. CONCLUSION AND CLINICAL RELEVANCE: Subjects with seasonal allergy can be used to determine immunomodulatory responses outside the pollen season within a 4-week study period. L. plantarum CBS125632 decreased several immune markers related to allergy, and may have the potential to alleviate the severity of seasonal allergy symptoms.


Assuntos
Alérgenos/imunologia , Betula/imunologia , Lactobacillus plantarum/imunologia , Pólen/imunologia , Rinite Alérgica Sazonal/imunologia , Adolescente , Adulto , Alérgenos/isolamento & purificação , Feminino , Humanos , Interleucina-10/biossíntese , Interleucina-10/imunologia , Lactobacillus plantarum/isolamento & purificação , Masculino , Pessoa de Meia-Idade , Adulto Jovem
3.
J Gen Physiol ; 108(6): 497-514, 1996 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-8972388

RESUMO

We have measured the rate of heat production of isolated, quiescent, right ventricular trabeculae of the rat under isosmotic and hyperosmotic conditions, using a microcalorimetric technique. In parallel experiments, we measured force production and intracellular calcium concentration ([Ca2+]i). The rate of resting heat production under isosmotic conditions (mean +/- SEM, n = 32) was 100 +/- 7 mW (g dry wt)-1; it increased sigmoidally with osmolality, reaching a peak that was about four times the isosmotic value at about twice normal osmotic pressure. The hyperosmotic thermal response was: (a) abolished by anoxia, (b) attenuated by procaine, (c) insensitive to verapamil, ouabain, and external calcium concentration, and (d) absent in chemically skinned trabeculae bathed in low-Ca2+ "relaxing solution." Active force production was inhibited at all osmolalities above isosmotic. Passive (tonic) force increased to, at most, 15% of the peak active force developed under isosmotic conditions while [Ca2+]i increased, at most, 30% above its isosmotic value. We infer that hyperosmotic stimulation of resting cardiac heat production reflects, in large part, greatly increased activity of the sarcoplasmic reticular Ca2+ ATPase in the face of increased efflux via a procaine-inhibitable Ca(2+)-release channel.


Assuntos
Coração/fisiologia , Temperatura Alta , Animais , Cálcio/metabolismo , Calorimetria , Coração/efeitos dos fármacos , Técnicas Histológicas , Técnicas In Vitro , Membranas Intracelulares/metabolismo , Contração Isométrica , Masculino , Miocárdio/metabolismo , Concentração Osmolar , Ouabaína/farmacologia , Oxigênio/farmacologia , Ratos
4.
Behav Res Ther ; 43(6): 733-46, 2005 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-15890166

RESUMO

The social skills rating system (SSRS) was developed to assess social skills of children, as observed by multiple raters (teacher, parent, child). Studies of the SSRS have been conducted with handicapped, mentally retarded and learning disabled children. No studies have reported the psychometric properties of the SSRS in a clinical ADHD sample. This is important, because deficient social functioning is associated with ADHD. The present study assesses the psychometric properties of the teacher, parent and child versions of the SSRS in children with ADHD (n = 123), and normal controls (n = 239). Also, the social skills of children with ADHD, as rated on the SSRS were examined. Results support the factor structure and internal consistency of the original SSRS-teacher version. Moreover, support was found for 3 out of 4 scales of the SSRS-parent version. The factor structure of the SSRS-child version could not be replicated. An explanatory factor analysis on the SSRS-child version yielded two factors. Evidence was found for discriminative ability of the SSRS between normal controls and children with ADHD. Finally, informant agreement between raters was found to be poor.


Assuntos
Transtorno do Deficit de Atenção com Hiperatividade/psicologia , Relações Interpessoais , Criança , Análise Fatorial , Feminino , Humanos , Masculino , Psicometria
5.
Contraception ; 67(3): 187-94, 2003 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-12618252

RESUMO

The acceptability of the combined contraceptive vaginal ring, NuvaRing, was assessed during two trials conducted in North America and Europe. Women completed a questionnaire about the ring's clarity of instructions, ease of use, sexual comfort, cycle-related characteristics and satisfaction after 3, 6 and 13 cycles of use. A total of 1,950 women (82% of those recruited) completed a questionnaire at cycle 3. At baseline, 66% of participants preferred oral contraceptives, but after three cycles of ring use 81% preferred the ring. On study completion, 97% agreed that the instructions for use were clear; 85% of women and 71% of their partners never/rarely felt the ring during intercourse and 94% of partners never/rarely minded that the woman was using the ring. Overall acceptance was high, 96% were satisfied with the ring and 97% would recommend the ring. Similar responses were seen for women who prematurely discontinued from the studies, except that slightly fewer women were satisfied (60%) and would recommend the ring (75%). Reasons for liking the ring included 'not having to remember anything' (45%) and 'ease of use' (27%). In conclusion, there is a high level of user and partner acceptability for the contraceptive ring.


Assuntos
Anticoncepcionais Femininos/administração & dosagem , Dispositivos Anticoncepcionais Femininos , Desogestrel , Etinilestradiol/administração & dosagem , Satisfação do Paciente , Compostos de Vinila/administração & dosagem , Adolescente , Adulto , Coito/fisiologia , Europa (Continente) , Feminino , Humanos , Masculino , América do Norte , Inquéritos e Questionários , Vagina/fisiologia
6.
Clin Oncol (R Coll Radiol) ; 25(3): 190-6, 2013 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-23257248

RESUMO

AIMS: The treatment of intermediate- to high-risk prostate cancer with radical radiotherapy is usually in combination with neoadjuvant androgen deprivation therapy. The aim of the present trial was to investigate whether degarelix achieves comparable efficacy with that of goserelin plus bicalutamide as neoadjuvant therapy before radiotherapy. MATERIALS AND METHODS: The study was a randomised, parallel-arm, active-controlled, open-label trial in 244 men with a UICC prostate cancer TNM category T2b-T4, N0, M0, Gleason score ≥7, or prostate-specific antigen ≥10 ng/ml and a total prostate volume >30 ml, who were scheduled to undergo radical radiotherapy and in whom neoadjuvant androgen deprivation therapy was indicated. Eligible patients received treatment with either monthly degarelix (240/80 mg) or goserelin (3.6 mg) for 12 weeks, the latter patients also receiving bicalutamide (50 mg) for 17 days initially. The primary efficacy measure was the mean percentage reduction in total prostate volume from baseline at week 12 measured by transrectal ultrasound. The severity and relief of lower urinary tract symptoms were assessed by the International Prostate Symptom Score questionnaire. Quality of life was assessed by the eighth question of the International Prostate Symptom Score. About 50% of the patients had moderate to severe lower urinary tract symptoms at baseline. RESULTS: The total prostate volume decreased significantly from baseline to week 12 in both treatment groups, reaching -36.0 ± 14.5% in degarelix-treated patients and -35.3 ± 16.7% in goserelin-treated patients (adjusted difference: -0.3%; 95% confidence interval: -4.74; 4.14%). At the end of the therapy, more degarelix- than goserelin-treated patients reported International Prostate Symptom Score decreases of ≥3 points (37% versus 27%, P = 0.21). In addition, in patients with a baseline International Prostate Symptom Score of ≥13, the magnitude of the decrease was larger in degarelix- (n = 53) versus goserelin-treated patients (n = 17) (6.04 versus 3.41, P = 0.06). CONCLUSIONS: The efficacy of degarelix in terms of prostate shrinkage is non-inferior to that of goserelin plus bicalutamide. The added benefits of degarelix in terms of more pronounced lower urinary tract symptom relief in symptomatic patients could be the reflection of differences in the direct effects on extra-pituitary receptors in the lower urinary tract [Clinicaltrials.gov ID: NCT00833248].


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Oligopeptídeos/uso terapêutico , Neoplasias da Próstata/tratamento farmacológico , Neoplasias da Próstata/radioterapia , Idoso , Antagonistas de Androgênios/efeitos adversos , Antagonistas de Androgênios/uso terapêutico , Anilidas/administração & dosagem , Anilidas/efeitos adversos , Antineoplásicos Hormonais/efeitos adversos , Antineoplásicos Hormonais/uso terapêutico , Protocolos de Quimioterapia Combinada Antineoplásica/efeitos adversos , Gosserrelina/administração & dosagem , Gosserrelina/efeitos adversos , Humanos , Calicreínas/sangue , Masculino , Terapia Neoadjuvante , Nitrilas/administração & dosagem , Nitrilas/efeitos adversos , Oligopeptídeos/efeitos adversos , Antígeno Prostático Específico/sangue , Neoplasias da Próstata/sangue , Neoplasias da Próstata/patologia , Qualidade de Vida , Fatores de Risco , Testosterona/sangue , Compostos de Tosil/administração & dosagem , Compostos de Tosil/efeitos adversos
7.
Prostate Cancer Prostatic Dis ; 14(2): 184-90, 2011 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-21445092

RESUMO

The aim of the study was to compare the onset, incidence and frequency/intensity of hot flushes during androgen-deprivation therapy with a gonadotropin-releasing hormone antagonist (GnRH) blocker versus an agonist using data from a randomized Phase 3 clinical trial. In total, 610 prostate cancer patients received monthly degarelix (s.c., 240/80 mg, n=207, or 240/160 mg, n=202) or leuprolide (i.m., 7.5 mg, n=201) for 12 months. Data on hot flushes was collected as self-reported adverse events and in a subgroup of 254 patients with electronic diaries. The onset of hot flushes was faster on degarelix versus leuprolide, and was accompanied by higher median hot flush scores during the first 3 months. However, there were no significant differences in overall incidence rates and median hot flush scores over the entire 12 months. After the third month, incidence rates dropped below 6%, whereas prevalence rates remained constant in all the three treatment arms. In multivariate analysis, body weight and heart rate at baseline were independent predictors of hot flushes (P<0.05). Except for a more rapid onset with the GnRH antagonist, there were no major differences in the overall pattern of hot flushes between treatment options. Weight control may help to minimize the incidence of hot flushes.


Assuntos
Antineoplásicos Hormonais/uso terapêutico , Rubor/induzido quimicamente , Hormônio Liberador de Gonadotropina/antagonistas & inibidores , Leuprolida/uso terapêutico , Oligopeptídeos/uso terapêutico , Neoplasias da Próstata/tratamento farmacológico , Idoso , Idoso de 80 Anos ou mais , Antineoplásicos Hormonais/efeitos adversos , Peso Corporal , Rubor/epidemiologia , Seguimentos , Frequência Cardíaca , Humanos , Leuprolida/efeitos adversos , Masculino , Pessoa de Meia-Idade , Oligopeptídeos/efeitos adversos , Fatores de Risco , Autorrelato , Resultado do Tratamento
8.
Kidney Int ; 71(5): 417-24, 2007 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-17213874

RESUMO

Aldosterone has pro-fibrotic properties and is a potential target for additional intervention in patients with chronic renal disease showing resistance to therapy during treatment with angiotensin-converting enzyme inhibitors (ACEi). Combining ACEi and aldosterone receptor blockade (aldoRB) in proteinuric renal disease reduces proteinuria, but effects on proteinuria-induced renal damage are unknown. We studied the effect of ACEi/aldoRB in adriamycin nephrosis (AN). Six weeks after injection of adriamycin in Wistar rats, randomized treatment with vehicle (VEH, n=8), aldoRB (n=12), ACEi (n=10), or a combination of ACEi/aldoRB (n=14) was given for 12 weeks. Healthy rats served as controls (n=6). Renal damage was quantified by markers of tubular injury (osteopontin (OPN) and kidney injury molecule-1 (Kim-1)), pre-fibrotic lesions (alpha-smooth muscle actin (SMA)), interstitial fibrosis (IF), and focal glomerulosclerosis (FGS). In AN animals, proteinuria was increased compared with controls. ACEi and ACEi/aldoRB significantly reduced proteinuria compared with VEH, whereas aldoRB monotherapy was without effect. Blood pressure was reduced in ACEi and ACEi/aldoRB compared with VEH and aldoRB. OPN and Kim-1 were increased in AN animals, but significantly reduced by ACEi/aldoRB. Treatment with ACEi and ACEi/aldoRB prevented an increase of SMA, IF, and FGS. In conclusion, ACEi/aldoRB effectively reduced proteinuria and markers of tubular injury and prevented renal damage in this rat model of chronic proteinuria-induced renal damage.


Assuntos
Inibidores da Enzima Conversora de Angiotensina/uso terapêutico , Antagonistas de Receptores de Mineralocorticoides/uso terapêutico , Nefrose/tratamento farmacológico , Proteinúria/tratamento farmacológico , Actinas/análise , Aldosterona/metabolismo , Animais , Biomarcadores/análise , Pressão Sanguínea/efeitos dos fármacos , Moléculas de Adesão Celular/análise , Colágeno Tipo IV/análise , Modelos Animais de Doenças , Quimioterapia Combinada , Glomerulosclerose Segmentar e Focal/prevenção & controle , Rim/química , Rim/patologia , Proteínas de Membrana/análise , Nefrose/etiologia , Nefrose/patologia , Osteopontina/análise , Peptidil Dipeptidase A/metabolismo , Proteinúria/complicações , Ratos , Ratos Wistar
9.
Am J Physiol Heart Circ Physiol ; 278(4): H1233-40, 2000 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-10749719

RESUMO

We developed an organoid culture technique to study the mechanisms involved in arterial remodeling. Resistance arteries were isolated from rat cremaster muscle and mounted in a pressure myograph at 75 mmHg. Vessels were studied during a 4-day culture period in DMEM with either 2% albumin, 10% heat-inactivated FCS (HI-FCS) or 10% dialyzed HI-FCS (12 kDa cut off) added to the perfusate. The albumin group showed a gradual loss of endothelial function and integrity, whereas smooth muscle agonist and myogenic responses were retained. No remodeling was observed. Vessels cultured in the presence of serum showed a progressive constriction. Smooth muscle responses and substance P-induced endothelium-dependent dilation were maintained. An inward remodeling of 17 +/- 4% in the HI-FCS group and 26 +/- 3% in the dialyzed HI-FCS group was found, while media cross-sectional areas were unchanged. These data show that pressurized resistance arteries can be maintained in culture for several days and undergo eutrophic remodeling in vitro in the presence of high molecular weight serum factors.


Assuntos
Endotélio Vascular/fisiologia , Proteínas Fetais/farmacologia , Músculo Liso Vascular/fisiologia , Resistência Vascular/fisiologia , Acetilcolina/farmacologia , Albuminas/farmacologia , Animais , Anti-Hipertensivos/farmacologia , Pressão Sanguínea/fisiologia , Cateterismo , Endotélio Vascular/efeitos dos fármacos , Endotélio Vascular/ultraestrutura , Sequestradores de Radicais Livres/farmacologia , Temperatura Alta , Ketanserina/farmacologia , Losartan/farmacologia , Masculino , Microscopia Eletrônica , Músculo Liso Vascular/efeitos dos fármacos , Músculo Liso Vascular/ultraestrutura , Técnicas de Cultura de Órgãos/métodos , Ratos , Ratos Wistar , Serotonina/farmacologia , Substância P/farmacologia , Resistência Vascular/efeitos dos fármacos , Vasoconstrição/efeitos dos fármacos , Vasoconstrição/fisiologia , Vasodilatadores/farmacologia
10.
Comput Biomed Res ; 18(4): 377-90, 1985 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-2931237

RESUMO

Electrocardiographic measurements from two groups, patients with left ventricular hypertrophy and clinically normal cases, were analyzed to illustrate the performance of the linear logistic discrimination method in the case of very unequal covariance matrices. Two quadratic extensions of the linear model were critically investigated. The use of graphical methods to check the model has been stressed and illustrated.


Assuntos
Biometria , Cardiomegalia/diagnóstico , Cardiomegalia/fisiopatologia , Eletrocardiografia , Estudos de Avaliação como Assunto , Humanos , Sistemas de Informação
11.
Exp Physiol ; 86(5): 585-92, 2001 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-11571485

RESUMO

The regulation of vascular tone includes modulation of contractile element calcium sensitivity. We tested the involvement of the Rho-associated protein kinase p160ROCK in tone and calcium sensitivity of cannulated rat mesenteric small arteries. These vessels developed basal tone and showed myogenic responses upon pressure steps, resulting from an increase in calcium in combination with a high contractile element calcium sensitivity. Y-27632, believed to be a specific p160ROCK inhibitor, caused concentration-dependent inhibition of basal tone, with near full inhibition at 3 microM. At this concentration, myogenic responses were absent and stepwise pressure elevation resulted in severe vascular distension. Y-27632 did not affect pressure-induced changes in intracellular calcium but rather reduced pressure-induced as well as phenylephrine-induced calcium sensitisation. Thus in the presence of the blocker, for a given calcium concentration, tone was greatly reduced, and the divergence in sensitivity between pressure and phenylephrine as stimuli on the one hand and potassium on the other disappeared. K+ (125 mM) and ionomycin still caused contraction in the presence of the p160ROCK blocker. These data show that in pressurised small arteries the Rho-p160ROCK pathway is active in the absence of vasoconstrictors, keeping the vessels in a state of high calcium sensitivity and basal tone.


Assuntos
Cálcio/metabolismo , Artérias Mesentéricas/fisiologia , Proteínas Serina-Treonina Quinases/metabolismo , Amidas/farmacologia , Animais , Interações Medicamentosas , Peptídeos e Proteínas de Sinalização Intracelular , Ionomicina/farmacologia , Ionóforos/farmacologia , Masculino , Artérias Mesentéricas/efeitos dos fármacos , Artérias Mesentéricas/metabolismo , Contração Muscular , Relaxantes Musculares Centrais/farmacologia , Tono Muscular , Músculo Liso Vascular/efeitos dos fármacos , Músculo Liso Vascular/metabolismo , Fenilefrina/farmacologia , Potássio/metabolismo , Proteínas Serina-Treonina Quinases/antagonistas & inibidores , Piridinas/farmacologia , Ratos , Ratos Wistar , Vasoconstrição/fisiologia , Vasoconstritores/farmacologia , Quinases Associadas a rho
12.
Clin Chem ; 40(9): 1698-702, 1994 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-8070078

RESUMO

The evaluation of a biochemical or hematological quantity measured in a study group of employees during occupational health assessments involves a comparison with a reference sample group. Part of this evaluation consists of checking whether the percentage of values larger than a predetermined upper reference limit is significantly larger than the percentage normally expected (2.5%, if the 97.5 percentile is used as the upper reference limit). The reference limit, however, is estimated from a random reference sample, the size of which, for many reasons, may be relatively small; as a consequence, the reference limit estimate will be imprecise. In situations in which the reference sample size is smaller than or not much larger than the study sample size, this imprecision results in the usual binomial test of significance being highly inappropriate. We provide an exact nonparametric test valid for all reference sample sizes.


Assuntos
Saúde Ocupacional , Padrões de Referência , Estatística como Assunto , Adulto , Testes Hematológicos , Humanos , Masculino , Estudos de Amostragem
13.
Clin Exp Pharmacol Physiol ; 28(10): 848-55, 2001 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-11553027

RESUMO

1. The present study was designed to determine the role of protein kinase C (PKC) in the myogenic response of small arteries. In particular, we tested whether inhibition of PKC reverses the previously found pressure-induced elevation of contractile element calcium sensitivity. 2. Rat mesenteric small arteries were cannulated and pressurized. The internal diameter was continuously monitored with a video camera and intracellular calcium levels were measured by means of fura-2. Myogenic responses were observed when the pressure was raised stepwise from 20 to 60 and then to 100 mmHg in physiological saline solution and during application of phenylephrine (0.1 or 1 micromol/L) or potassium (36 mmol/L). 3. The PKC inhibitors H-7 (20 micromol/L), staurosporine (100 nmol/L) and calphostin C (10 nmol/L) all completely abolished the myogenic response. Whereas staurosporine caused an ongoing reduction in intracellular calcium, pressure-induced calcium transients were not affected by either H-7 or calphostin C. In particular, the slope of the wall tension-calcium relationship remained similar in the presence of both H-7 and calphostin C, despite an upward shift of this relationship to higher calcium levels in the case of calphostin C. 4. These results show that activity of PKC isoform(s) is essential for myogenic calcium-contraction coupling.


Assuntos
Cálcio/metabolismo , Artérias Mesentéricas/enzimologia , Contração Muscular , Proteína Quinase C/fisiologia , Esteroides , 1-(5-Isoquinolinasulfonil)-2-Metilpiperazina/farmacologia , Animais , Cateterismo , Inibidores Enzimáticos/farmacologia , Masculino , Artérias Mesentéricas/efeitos dos fármacos , Contração Muscular/efeitos dos fármacos , Músculo Liso Vascular/efeitos dos fármacos , Músculo Liso Vascular/enzimologia , Naftalenos/farmacologia , Proteína Quinase C/antagonistas & inibidores , Ratos , Ratos Wistar , Saponinas/farmacologia , Vasoconstrição/efeitos dos fármacos
14.
J Mol Cell Cardiol ; 29(5): 1341-54, 1997 May.
Artigo em Inglês | MEDLINE | ID: mdl-9201620

RESUMO

The present study was designed in order to investigate more precisely the role of calcium homeostasis maintenance in protein kinase C (PKC) mediated preconditioning. We used a 15 min pre-incubation period, with 1 mumol/l exogenous norepinephrine (NE) to pharmacologically precondition isolated, superfused rat trabeculae against contractile dysfunctioning following 120 min of metabolic inhibition (MI, in 2 mmol/l CN- containing Tyrode without glucose at 1 Hz stimulation frequency). Contractile recovery was studied during a subsequent 60 min recovery period (RP, in glucose containing Tyrode at 0.2 Hz). Tyrode was gassed with 95%, O2/ 5% CO2 and kept at a constant temperature of 24 degrees C. Force and intracellular free calcium ([Ca2+]i) were monitored throughout the experimental protocol; [Ca2+]i was measured using fura-2. Pretreatment with NE (group NE-I) significantly increased the fraction of trabeculae that resumed to contract during RP, from 36 +/- 13% (mean +/- S.E.M.) in controls to 82 +/- 10% (P < 0.05). In correspondence with this, NE-pretreatment increased the proportion of trabeculae in which the Ca2+ rise from the onset of rigor development during MI was attenuated. After 40 min of MI [Ca2+]i in the failing control, as well as failing group NE-I, trabeculae (1.08 +/- 0.20 and 1.51 +/- 0.26 mumol/l, respectively) was increased significantly compared to the mean value registered in the recovering preparations of these groups (0.34 +/- 0.04 mumol/l: P < 0.05). Specific inhibition of PKC with 2 mumol/l chelerythrine (group NE-IV) almost completely blocked the protection induced by NE-pretreatment, including its protective action against Ca2+ overload, i.e. the fraction of trabeculae that resumed to contract during RP returned to untreated control level (46 +/- 11%: P < 0.05 v group NE-I). Also in this case [Ca2+]i in the failing group NE-IV trabeculae after 40 min of MI was increased substantially, compared to the value measured in the recovering preparations (4.75 +/- 1.00 and 0.60 +/- 0.08 mumol/ l, respectively). The relative importance of both alpha-adrenergic and beta-adrenergic receptor pathways in this preconditioning-like effect of NE-pretreatment, was investigated using specific blockers. The results point to an alpha 1-adrenergic receptor mediated signaling mechanism, which enhances PKC-dependent control of [Ca2+]i from the onset of rigor development during MI.


Assuntos
Agonistas alfa-Adrenérgicos/farmacologia , Cálcio/metabolismo , Contração Miocárdica/efeitos dos fármacos , Miocárdio/metabolismo , Norepinefrina/farmacologia , Proteína Quinase C/metabolismo , Tetralonas , Antagonistas Adrenérgicos alfa/farmacologia , Antagonistas Adrenérgicos beta/farmacologia , Alcaloides , Animais , Benzofenantridinas , Inibidores Enzimáticos/farmacologia , Coração/efeitos dos fármacos , Ventrículos do Coração/efeitos dos fármacos , Ventrículos do Coração/metabolismo , Precondicionamento Isquêmico Miocárdico , Masculino , Miocárdio/enzimologia , Fenantridinas/farmacologia , Fenetilaminas/farmacologia , Propranolol/farmacologia , Proteína Quinase C/antagonistas & inibidores , Ratos , Ratos Wistar , Transdução de Sinais
15.
Am J Physiol ; 268(4 Pt 2): H1510-20, 1995 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-7733352

RESUMO

The beneficial effect of low pH during cardiac ischemia on reperfusion injury has often been attributed to its energy-saving effect due to inhibition of contraction. The role of low pH on Ca2+ accumulation and muscle tension was assessed in energy-depleted tissue by changing the pH of the medium from 7.4 to 6.2 at onset of rigor development during metabolic inhibition (MI), i.e., in the energy-depleted phase. Cytosolic free Ca2+ ([Ca2+]i) and intracellular H+ (pHi) were measured in rat trabeculae at 20 degrees C with fura 2 and 2',7'-bis(carboxyethyl)-5(6)-carboxyfluorescein, respectively, and tension was recorded. The preparations were energy depleted by stimulation at 1 Hz in glucose-free Tyrode solution with 2 mM NaCN. Rigor developed within 20 min, indicating energy depletion. Resting [Ca2+]i was followed during 50 min (group I) or 100 min (group II) of rigor, and recovery was followed for 60 min in glucose-containing Tyrode solution at 0.2-Hz stimulation. Resting [Ca2+]i rose within 50 min (group I) but stabilized in the 50- to 100-min period (group II). All preparations from group I (n = 5) resumed contraction in the recovery period but in group II (n = 10) 70% failed to recover, and [Ca2+]i remained elevated compared with those that recovered. An extracellular pH of 6.2, resulting in similar pHi, from onset of rigor development (group III) led to only a modest rise in [Ca2+]i during the 100-min rigor period, and all preparations resumed contraction after approximately 3 min in normal medium. ATP was very low in all groups at the end of MI but was still significantly lower in group II than in groups I and III. A beneficial energy-sparing effect of low pH during the rigor phase can therefore not be excluded. We conclude that 1) the capacity of trabeculae to recover from MI depends on the time period and magnitude of the [Ca2+]i rise in the energy-depleted phase and 2) low pH in energy-depleted trabeculae protects against Ca overload, improving recovery after normalization of perfusion conditions.


Assuntos
Cálcio/fisiologia , Metabolismo Energético , Concentração de Íons de Hidrogênio , Contração Miocárdica/fisiologia , Miocárdio/metabolismo , Animais , Citosol/metabolismo , Estimulação Elétrica , Fluoresceínas , Corantes Fluorescentes , Ratos , Cianeto de Sódio/farmacologia
16.
J Mol Cell Cardiol ; 30(2): 435-40, 1998 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-9515020

RESUMO

We have recently shown that norepinephrine (NE) pretreatment attenuates Ca2+ overloading in cardiac rat trabeculae during metabolic inhibition (MI) with NaCN (2 mmol/l), and improves contractile recovery during a subsequent recovery period (RP). In the present study, we investigated the effects of the continuous presence of NE (1 micro mol/l), i.e. before, during and after MI, on Ca2+ homeostasis maintenance and contractile recovery in the same model at 24 degrees C. In addition, we tested the effects of NE when only present in the rigor period during MI. The continuous presence of NE both before (30 min) and during MI (120 min)+RP (60 min) (group NE-I) significantly increased the proportion of trabeculae that resumed to contract during RP from 46+/-4% (mean+/-s.e.m.) in controls to 82+/-8%. The Ca2+ rise at the end of MI in failing control trabeculae (1.85+/-0.04 micro mol/l) was more than doubled compared to recovering control preparations (0.78+/-0.02 micro mol/l). However, the time-course of the Ca2+ rise during MI in recovering and failing NE-I preparations was similar, and eventually of the same magnitude as observed in failing control preparations (1.6+/-0. 02 and 1.85+/-0.07 micro mol/l, respectively). In contrast, when NE was present only in the rigor period during MI (group NE-II) the proportion of recovering preparations decreased significantly to 27+/-9%. Similar to the control group, recovering and failing preparations in group NE-II could be distinguished by a differential course in the Ca2+ rise during MI. The results show that when NE is present both before and during MI+RP, (i) recovery probability following MI is still improved, in spite of the deleterious effect on contractile recovery of the presence of NE in the rigor during MI, and (ii) there is no relationship between the magnitude of Ca2+ overload during MI and recovery probability during RP.


Assuntos
Contração Miocárdica/efeitos dos fármacos , Isquemia Miocárdica/fisiopatologia , Norepinefrina/farmacologia , Trifosfato de Adenosina/metabolismo , Animais , Cálcio/metabolismo , Técnicas In Vitro , Transporte de Íons/efeitos dos fármacos , Precondicionamento Isquêmico Miocárdico , Masculino , Contração Miocárdica/fisiologia , Isquemia Miocárdica/metabolismo , Traumatismo por Reperfusão Miocárdica/metabolismo , Traumatismo por Reperfusão Miocárdica/fisiopatologia , Traumatismo por Reperfusão Miocárdica/prevenção & controle , Norepinefrina/fisiologia , Ratos , Fatores de Tempo
17.
Eur J Contracept Reprod Health Care ; 8(2): 87-92, 2003 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-12836662

RESUMO

A new guideline on the clinical investigation of steroid contraceptives in women, which has been released by the European Agency for the Evaluation of Medicinal Products (EMEA), calls for the calculation of a confidence interval for the Pearl Index, a widely used measure to describe the effectiveness of a contraceptive method. However, the interpretation of the Pearl Index as a statistical parameter, for which a confidence interval can be calculated, needs further clarification. The guideline does not provide the necessary definitions. In this paper, two statistical models, the Bernoulli model and the Poisson model, are compared; both can be used for the calculation of the Pearl Index and its upper confidence limit. The Poisson model proved to be more suitable, because it can accommodate incomplete treatment cycles. Unambiguous definitions and statistical formulae for the calculation of overall Pearl Index and the Method Failure Pearl Index are given. Finally, the sample sizes required to fulfill the EMEA's guideline are given.


Assuntos
Anticoncepção/estatística & dados numéricos , Modelos Estatísticos , Gravidez/estatística & dados numéricos , Intervalos de Confiança , Anticoncepcionais Orais/administração & dosagem , Europa (Continente) , Feminino , Diretrizes para o Planejamento em Saúde , Humanos , Tamanho da Amostra
18.
Clin Chem ; 39(7): 1375-81, 1993 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-8101144

RESUMO

For studying trends in blood biochemistry analytes of an individual or a group of individuals, the outcome may be influenced by analytical changes that may have occurred during the study. An observed trend may well represent a drift in analytical performance instead of a truly biological finding. We developed a model that allows for retrospective correction of analytical changes with time. This model is based on the concept of adjustment of an individual's longitudinal blood biochemistry data by comparing the long-term results of the laboratory with those of other laboratories in an external quality-control survey program. Factors responsible for the analytical bias of our laboratory were identified by multiple regression analysis. The resulting procedure for assessing analytical bias and variability was applied to study in two mutually exclusive cohorts of employees of the Shell petrochemical complex in Rotterdam (a) the true nature of the changes (analytical or biological) in gamma-glutamyltransferase (GGT) and (b) the effect of age on GGT. The first cohort consisted of employees who attended a periodic health assessment in 1984 and in 1989; the second, employees who attended periodic health assessments in 1985 and in 1988. Thus we studied 3- and 5-year changes of GGT corrected for analytical bias. Whereas standard cross-sectional results apparently showed an increase of GGT up to age 50 years, the longitudinal findings corrected for analytical changes, as indicated above, do not support these cross-sectional results.


Assuntos
Envelhecimento/sangue , gama-Glutamiltransferase/sangue , Adolescente , Adulto , Humanos , Estudos Longitudinais , Pessoa de Meia-Idade , Controle de Qualidade , Análise de Regressão
19.
J Mol Cell Cardiol ; 31(5): 1083-94, 1999 May.
Artigo em Inglês | MEDLINE | ID: mdl-10336846

RESUMO

The authors have previously shown that norepinephrine (NE) pretreatment attenuates Ca2+ overloading in cardiac rat trabeculae during metabolic inhibition, and improves contractile function during a subsequent recovery period. The present study investigated: (i) whether protection of sarcoplasmic reticulum (SR) function during metabolic inhibition (MI) is involved in the preconditioning-like effect of NE-pretreatment, and (ii) whether or not this process is PKC-dependent. A 15 min preincubation period was used with 1 micromol/l exogenous NE to precondition isolated, superfused rat trabeculae against contractile dysfunctioning following 40 min of MI in 2 mmol/l NaCN containing Tyrode (gassed with 95% O2/5% CO2; pH 7.4, 24 degrees C) without glucose at 1-Hz stimulation frequency. Contractile recovery was studied during a subsequent 60 min recovery period (RP) in glucose containing Tyrode at 0.2 Hz. Force and intracellular free calcium ([Ca2+]ii) were monitored throughout the experimental protocol. Pretreatment of trabeculae with NE (group NE) substantially diminished the Ca2+ rise from the onset of rigor development during MI, compared to preparations which were pretreated with NE, in the presence of specific PKC blocker chelerythrine (2 micromol/l; group NE+CHEL). After 40 min of MI, resting [Ca2+]i in group NE and NE+CHEL was increased to 0.50+/-0.03 and 2.08+/-0.20 micromol/l, respectively (P<0.05), whereas total intracellular ATP levels were similar in both groups (approximately 0.20 micromol/g dry wt). This corresponded with an increase in active force development (119%) and a decrease in twitch force relaxation time (77%) during subsequent RP in group NE, compared to pre-MI values of the same group. In contrast, a significant decrease in force recovery (54%) and an increase in twitch force relaxation time (123%) was observed in group NE+CHEL. Values for [Ca2+]i, contractile recovery, and twitch force relaxation time in untreated controls as well as CHEL preparations corresponded to those measured in the NE+CHEL group. Rapid cooling contractures (RCCs), which provide information on both SR-Ca2+ loading and Ca2+ re-uptake activity, revealed a 2-fold higher SR Ca2+ content during RP in group NE compared to controls and group NE+CHEL. In addition, kinetic analysis of the RCC rewarming spike (RWS) showed that this was accompanied by greater than a 28% increase in the maximum rate of RWS relaxation (-dF/dt/rws) in group NE compared to group NE+CHEL. The change of -dF/dt/rws in the NE group during RP following MI persisted after SR Ca2+-release channel blockade by ryanodine treatment (100 micromol/l), which suggests involvement of NE-induced, PKC-dependent protection of SR Ca2+-ATPase activity. The results of the present study point to an inverse relationship between the Ca2+ rise during MI and SR functioning, in which PKC appears to play a key role. It is concluded that the preconditioning-like effect of NE-pretreatment on contractile recovery is at least partly mediated by protection of SR function.


Assuntos
Precondicionamento Isquêmico Miocárdico , Fibras Musculares Esqueléticas/efeitos dos fármacos , Norepinefrina/uso terapêutico , Proteína Quinase C/metabolismo , Retículo Sarcoplasmático/efeitos dos fármacos , Trifosfato de Adenosina/metabolismo , Animais , Cálcio/metabolismo , Homeostase , Masculino , Fibras Musculares Esqueléticas/metabolismo , Contração Miocárdica/efeitos dos fármacos , Ratos , Ratos Wistar , Rianodina/uso terapêutico , Retículo Sarcoplasmático/metabolismo
20.
Anal Quant Cytol Histol ; 13(5): 307-15, 1991 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-1801828

RESUMO

An image analysis method of grading histologic sections of bladder carcinoma was tested. The method was new in four respects. First, for fixation of the biopsies a coagulant fixative was used. Second, 2-microns plastic sections were used to ensure the reproducibility of nuclear imaging. Third, a new stereologic approach was used for calculation of the nuclear volume and DNA content. Fourth, for the classification rule the morphometric, densitometric and texture features were used in concert. The IBAS 2000 instrument was used for the measurements. Texture analysis of the chromatin patterns was performed using Markovian texture features. Using discriminant analysis, of 22 parameters, 2 morphometric, 2 densitometric and 3 texture features were selected for the classification rule. With them, 89% of the bladder carcinomas were correctly classified into the three grades. All grade III tumors were classified correctly. Among the features tested, the densitometry of the DNA had the highest F values. All of the grade III tumors and 45% of the grade II tumor group had DNA histograms indicating aneuploidy. This study showed that plastic-embedded material is well suited to morphometry and densitometry and can be used for quantitative grading of bladder carcinoma.


Assuntos
Carcinoma de Células de Transição/patologia , Técnicas de Preparação Histocitológica , Processamento de Imagem Assistida por Computador/métodos , Neoplasias da Bexiga Urinária/patologia , Carcinoma de Células de Transição/classificação , Núcleo Celular/ultraestrutura , DNA de Neoplasias/análise , Humanos , Inclusão do Tecido/métodos , Preservação de Tecido , Neoplasias da Bexiga Urinária/classificação
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