RESUMO
Metallic pins and wires are frequently used for fixation of fractures and dislocations. Migration is one of the potential complications of such fixation methods. Usually, migration of the pins causes only minor complications, but if the device migrates to a vital cavity, serious damage and even death may ensue. The shoulder girdle is one of the areas in which pins and wires are mostly used, the humeral neck fractures being one of them. We report a case in which a Kirschner wire migrated from a subcapital humeral fracture site into the aorta and pericardium, causing sudden cardiac tamponade and death.
Assuntos
Fios Ortopédicos , Tamponamento Cardíaco/etiologia , Morte Súbita/etiologia , Migração de Corpo Estranho/complicações , Fraturas do Úmero/cirurgia , Feminino , Patologia Legal , Fixação Interna de Fraturas/instrumentação , Humanos , Pessoa de Meia-IdadeRESUMO
BACKGROUND: The ovarian hyperstimulation syndrome (OHSS) following ovulation induction is characterized by a cystic enlargement of the ovaries with an acute third space fluid sequestration. Inflammatory cytokines mediate the inflammatory response (IL-1, IL-2, IL-6, IL-8, TNFalpha) and play a crucial role in the pathogenesis of OHSS. OBJECTIVE: To determine the role of the anti-inflammatory cytokine interleukin-10 (IL-10) in OHSS and to examine its correlation with 17beta-estradiol and progesterone. STUDY DESIGN: Peritoneal fluid and serum samples were collected from 9 patients with severe OHSS after ovulation induction by administration of GnRH-analogues followed by hMG (n=5) or recombinant FSH (n=4). Patients (n=19) without pathological findings at laparoscopy served as non-pregnant controls and pregnant women (n=14) between 7 and 16 weeks of gestation served as positive controls. Samples were assayed for IL-10 by commercially available ELISA and for for 17beta-estradiol and progesterone by RIA. Statistical analysis was performed by non-parametric Mann-Whitney U-test and results are presented as the median and range. RESULTS: OHSS patients had significantly higher peritoneal fluid IL-10, 17beta-estradiol and progesterone levels than patients during early pregnancy and than the control group. No correlation was found between peritoneal fluid or serum IL-10 and 17beta-estradiol or progesterone in the different groups. Serum 17beta-estradiol and progesterone, but not serum IL-10 levels were elevated in OHSS and during early pregnancy. CONCLUSIONS: High concentrations of IL-10 in peritoneal fluid suggest a role of this anti-inflammatory cytokine during OHSS. 17beta-estradiol and progesterone were elevated in peritoneal fluid and serum during OHSS but no correlation with IL-10 concentrations was found. Therefore, we assume that IL-10 has a role in OHSS as a local mediator of inflammation, however, it presents different aspects of the OHSS than the sex steroids 17beta-estradiol and progesterone.
Assuntos
Líquido Ascítico/química , Hormônios Esteroides Gonadais/análise , Interleucina-10/análise , Síndrome de Hiperestimulação Ovariana/metabolismo , Adulto , Gonadotropina Coriônica/administração & dosagem , Estradiol/análise , Estradiol/sangue , Feminino , Fertilização in vitro , Hormônio Foliculoestimulante/administração & dosagem , Hormônio Liberador de Gonadotropina/análogos & derivados , Humanos , Interleucina-10/sangue , Menotropinas/administração & dosagem , Síndrome de Hiperestimulação Ovariana/sangue , Indução da Ovulação , Gravidez , Progesterona/análise , Progesterona/sangue , Proteínas RecombinantesRESUMO
The low rate of ongoing pregnancies in IVF cycles leads to a high number of repeated cycles in couples with previously failed attempts. Therefore it would be helpful to have a prediction about the chance of becoming pregnant in a repeated cycle. In a retrospective study the data of about 4246 cycles were analysed. Because the pregnancy rates in IVF- and ICSI cycles are generally different, these two groups were distinguished between and the outcome in patients with one, two or more attempts was analysed. The rate of ongoing pregnancies per patient was lower after IVF (24.9%) than after ICSI (32.9%), but was similar or even slightly increased in patients with more than one attempt. On the other hand, there was a high pregnancy rate with ICSI in the first two cycles (35.9%), but patients with more than two ICSI cycles had a significantly lower chance of becoming pregnant (20.7%). Factors that are known to influence the pregnancy rate, such as stimulation protocol, oocyte quality or number of transferred embryos, were similar in all groups. However, significantly reduced embryo quality with successive cycles was only observed in ICSI patients. There might be a negative selection of patients with poor embryo quality and previously failed attempts after ICSI, possibly due to an andrological factor. The differences between IVF- and ICSI patients are based on treatment indications, and andrological diseases are the predominant indication for ICSI. Although no correlation was found between changes in conventional sperm parameters and number of treated cycles, there might be a subgroup of andrological patients selected by repeatedly failed ICSI cycles. Chromosomal or genetic disturbances in spermatozoa of this subgroup could be the reason for failure.
Assuntos
Fertilização in vitro , Taxa de Gravidez/tendências , Adulto , Feminino , Fertilização in vitro/métodos , Humanos , Masculino , Microinjeções , Gravidez , Estudos RetrospectivosRESUMO
The purposes of the study were to compare treatment-related stresses of couples undergoing IVF or ICSI treatment (ejaculated, epididymal or testicular spermatozoa) and to identify sex differences and risk factors for depression. A one-year cohort of couples was retrospectively sent questionnaires on infertility and treatment-related distress and depression (Depression Scale, D-S). Two hundred and eighty-one women and 281 men (61% of those eligible) were included. As determined by analysis of the medical charts, successful couples were more likely to participate. Treatment-related distress was generally higher for women than for men. Treatment by ICSI carried additional burdens for the men: they reported a greater subjective responsibility for the infertility, impact of childlessness on daily life, treatment-related stresses (particularly for MESA/TESE) and time demands. Even when clinical differences between treatments (e.g. age, previous treatments) were controlled statistically, depression scores did not differ. Independent of the treatment, women were significantly more depressed than their age-matched female controls from the general population and their husbands. The men only reported marginally elevated depression scores compared to their controls. Meaningful characteristics were identified that could guide clinicians to give psychological support to those couples at risk for depression, e.g. an unsuccessful treatment outcome, repeated treatment cycles, a low socioeconomic status, foreign nationality, or, for women, a lack of partner support.
Assuntos
Depressão/etiologia , Fertilização in vitro/psicologia , Estresse Fisiológico/etiologia , Adulto , Feminino , Fertilização in vitro/métodos , Humanos , Infertilidade/psicologia , Masculino , Pessoa de Meia-Idade , Estudos RetrospectivosRESUMO
PURPOSE: To improve the chances of successful in vitro fertilization, spermatozoa have to be separated from semen before insemination. Therefore, sperm preparation methods are of great importance. METHODS: To obtain sufficient numbers of spermatozoa from patients with cryptozoospermia or severe OAT syndrome, only Minipercoll centrifugation and migration-sedimentation (MS) are practicable methods. The present study was performed to compare these two methods with regard to sperm concentration, motility, vitality, morphology, and chromatin condensation. The number of spermatozoa obtained after minipercoll was higher than that after MS, but sperm quality in all parameters examined was clearly better after MS than after Minipercoll. In the second stage of this study, the MS method was used for preparation of the spermatozoa for intracytoplasmic sperm injection (ICSI). RESULTS: Over a period of 13 months, 159 cycles were treated by ICSI. Of 1045 aspirated oocytes, 790 were injected. The fertilization rate was 70.4% of injected oocytes (556 oocytes with clearly visible pronuclei). In 146 cases, embryonic transfer was achieved; 58 patients became pregnant (39.7% per transfer and 36.5% per cycle). CONCLUSIONS: Although the abortion rate was very high (18 women lost their embryos), the results demonstrate that the microinjection method can be successfully used in combination with a MS method for preparation of spermatozoa.
Assuntos
Fertilização in vitro , Espermatozoides/metabolismo , Aborto Espontâneo , Morte Celular , Movimento Celular , Separação Celular/métodos , Centrifugação , Cromatina/metabolismo , Transferência Embrionária , Feminino , Fertilização in vitro/métodos , Humanos , Infertilidade/metabolismo , Masculino , Microinjeções/métodos , Oócitos/metabolismo , Povidona/uso terapêutico , Gravidez , Resultado da Gravidez , Sêmen/metabolismo , Dióxido de Silício/uso terapêutico , UrologiaRESUMO
In assisted reproductive medicine the controlled ovarian hyperstimulation enables several oocytes to be collected with the following transfer of more than one embryo and a higher pregnancy rate than in natural cycles. The most frequently used stimulation protocols are: i) clomiphene citrate (CC) and hMG stimulation; ii) hMG/FSH stimulation; iii) GnRH agonist (GnRH-a) and hMG/FSH stimulation, iiia) GnRH-a long protocol, iiib) GnRH-a short protocol, GnRH-a ultrashort protocol, iv) GnRH antagonist and hMG stimulation. The protocols are described and the advantages and disadvantages are discussed.
Assuntos
Indução da Ovulação , Técnicas Reprodutivas , Feminino , Humanos , Indução da Ovulação/métodos , GravidezRESUMO
Microsurgical epididymal sperm aspiration (MESA) and testicular sperm extraction (TESE) require close cooperation between andrologists, urologists and gynaecologists. Intracytoplasmic sperm injections were established in Giessen in March 1994 and embryo transfer (ET) was performed in 342 of 375 patients (91.2%). The percentage of pregnancies and ongoing pregnancies are 35.4% per ET (32.3% per cycle) and 25.1% per ET (22.9% per cycle), respectively. Microsurgical procedures such as epididymovasostomy or vasovasostomy and cryopreservation of human semen are also established methods. The purpose of the present study was to describe the andrological work-up for patients before MESA and TESE. Experiments demonstrate that incubation of testicular tissue samples in IVF medium and treatment with 1 mg ml-1 pentoxifylline increase the number of extracted motile spermatozoa. Centrifugation of the medium results in a further concentration of sperm cells. If no motile spermatozoa can be found in the supernatant medium, they may be extracted directly from the testicular tissue samples by means of a micromanipulator.
Assuntos
Epididimo/citologia , Espermatozoides , Testículo/citologia , Separação Celular/métodos , Epididimo/cirurgia , Feminino , Humanos , Inalação , Masculino , Microcirurgia , Gravidez , Cuidados Pré-Operatórios , Testículo/cirurgiaRESUMO
Tail stump syndrome, which may be associated with primary ciliary dyskinesia, is also associated with morphological defects of the flagellum resulting in severe asthenozoospermia. Until recently, these morphological anomalies caused definite male infertility. Today, however, new methods such as micromanipulation techniques provide a rational therapy for this patient group. A pregnancy followed by living offspring was achieved following the intracytoplasmic injection of immotile spermatozoa from a patient with tail stump syndrome.
Assuntos
Fertilização in vitro , Resultado da Gravidez , Cauda do Espermatozoide/patologia , Espermatozoides , Adulto , Citoplasma , Feminino , Humanos , Infertilidade Masculina/etiologia , Infertilidade Masculina/patologia , Masculino , Microinjeções , Gravidez , Motilidade dos Espermatozoides/fisiologia , Síndrome , Resultado do TratamentoRESUMO
Acrosin activity was determined using a gelatinolysis technique in 100-microliter semen aliquots of 114 patients (normozoospermia, n = 90; asthenozoospermia, n = 12; oligozoospermia, n = 10; polyzoospermia, n = 2) attending an in vitro fertilization (IVF) program. Halo diameter, halo formation rate, and a calculated acrosin activity index correlated significantly with the IVF rates (P = 0.0054, r = 0.396; P = 0.0009, r = 0.401; and P = 0.0003, r = 0.428, respectively). In cases where the halo diameter was < 10 microns and halo formation rate was < 60%, all patients were subfertile or infertile, that is, they showed poor or no fertilization in vitro, respectively. The assay demonstrated a relatively low sensitivity: 25.7% for halo diameter, 37.1% for halo formation rate, and 25.7% for acrosin activity index, respectively. This might be attributed to other sperm functional aspects, such as disturbed acrosome reaction or impaired zona binding.
Assuntos
Acrosina/metabolismo , Fertilização in vitro/métodos , Gelatina , Espermatozoides/metabolismo , Humanos , Infertilidade Masculina/metabolismo , MasculinoRESUMO
Hysterectomies are frequently required operations in gynecology. Several studies have reported an association between premenopausal hysterectomy and the risk of cardiovascular diseases. However, the pathophysiological linkages between these two conditions have not been elucidated. In recent years it has been shown that a decrease in plasma fibrinolytic activity is associated with increased risk of thrombosis. Furthermore, it has been known that the uterus is a very finbrinolytic active organ. In the present study we investigated the hypothesis that hysterectomy may lead to a decrease in plasma fibrinolytic activity, and thereby increase the risk for thromboembolic diseases. Fibrinolytic parameters of plasma were investigated in 26 women before and 6 weeks after premenopausal hysterectomy. Euglobulin lysis time (ELT), a global measure of plasma fibrinolytic activity, and the levels of tissue plasminogen activator (tPA) and plasminogen activator inhibitor type 1 (PAI-1) were not different before and after hysterectomy. The ELT difference before and after venous occlusion, which is a good indicator for the risk of thrombosis, was also not significantly changed after hysterectomy. Estradiol-17 beta, progesterone, LH, FSH and sex hormone binding globulin displayed no significant changes after hysterectomy. Furthermore, the hormone measurements also indicated that the women were premenopausal. There were no correlations between the hormone values and fibrinolytic parameters. These data indicate that premenopausal hysterectomy does not lead to changes in plasma fibrinolytic activity.
Assuntos
Fibrinólise , Histerectomia/efeitos adversos , Ovário/fisiologia , Pré-Menopausa , Adulto , Doenças Cardiovasculares/etiologia , Estradiol/sangue , Feminino , Hormônio Foliculoestimulante/sangue , Humanos , Pessoa de Meia-Idade , Inibidor 1 de Ativador de Plasminogênio/metabolismo , Fatores de Risco , Soroglobulinas/metabolismo , Ativador de Plasminogênio Tecidual/metabolismoRESUMO
The acrosome reaction was determined in aliquots from ejaculates of 74 patients undergoing in-vitro fertilization at the University of Giessen, Germany, by means of the triple-stain technique. The percentage of acrosome-reacted spermatozoa after low-temperature induction of the acrosome reaction was not significantly related with the fertilization rate (H test, P = 0.693, SJ test, P = 0.366). However, all patients showing < 13.0% acrosome-reacted spermatozoa had poor fertilization rates. Highly significant differences between patients could be detected by correlating the inducibility of the acrosome reaction with the fertilization rate (H test, P = 0.018; SJ test, P = 0.004); patients with high fertilization rates showed a corresponding high inducibility of acrosome reactions. From our results, it is evident that percentages of acrosome-reacted spermatozoa < 13.0% or an inducibility of the acrosome reaction of < 7.5% are indicative of subfertility.
Assuntos
Acrossomo/ultraestrutura , Fertilização in vitro , Humanos , Masculino , PrognósticoRESUMO
PROBLEM: Pharmacological doses of 17 beta-estradiol increase epidermal growth factor binding to uterine membranes. METHODS: To determine whether physiological elevated E2 concentrations in the preimplantation phase of rabbits and preovulatory phase of women cause epidermal growth factor (EGF) receptor expression, we performed radioligand binding studies of endometrial membranes with [125I]-EGF. RESULTS: Unmated rabbits revealed a binding maximum (Bmax) of 514 +/- 197 fmol/mg protein for [125I]-EGF. The Bmax values increased significantly to 1424 +/- 430 fmol/mg on day 1 and to 2244 +/- 224 fmol/mg on day 2 after mating. On day 3 the Bmax values decreased to 1409 +/- 238 fmol/mg and on days 4 to 8 the binding maxima were not significantly different from the Bmax values of unmated rabbits. In ovariectomized rabbits a significant increase of [125I]-EGF-binding could be mimicked 12 and 18 h after the intramuscular injection of estradiol (40 micrograms/kg). The estradiol-induced increase of [125I]-EGF Bmax values was blocked by the parallel application of the antiestrogen tamoxifen. Progesterone (2 mg/kg) did not influence [125I]-EGF-binding to endometrial membranes. Membrane preparations of the human endometrium from the periovulatory phase bound significantly more [125I]-EGF compared to endometrium of the early proliferative phase. The expression of EGF receptor mRNA was localized in the epithelial cells of the human endometrium by in situ hybridization technique. CONCLUSIONS: These results provide insight into the regulation of the autocrine and paracrine factor EGF in the endometrium during the preimplantation period.
Assuntos
Desenvolvimento Embrionário/fisiologia , Endométrio/citologia , Receptores ErbB/biossíntese , Estradiol/fisiologia , Adulto , Animais , Endométrio/metabolismo , Fator de Crescimento Epidérmico/metabolismo , Receptores ErbB/isolamento & purificação , Feminino , Fase Folicular/fisiologia , Humanos , Hibridização In Situ , Técnicas In Vitro , Radioisótopos do Iodo , Gravidez , RNA Mensageiro , Coelhos , Ensaio RadioliganteRESUMO
The increase in follicular diameter during maturation is accompanied by an increase in vascular supply. The oxygen tension (PO2) in the follicular fluid of the growing follicle should therefore give an insight whether the oxygen delivery during this pertinent process is sufficient. Follicular fluid of 20 patients subjected to in vitro fertilization and embryo transfer were sampled in heparinized glass capillaries which were placed between the puncturing needle and the collecting reservoir. All patients were treated with human menopausal gonadotropin (HMG) and follicle-stimulating hormone (FSH). The PO2, PCO2 and pH of the follicular fluid were measured with an automatic gas analyser (Ciba Corning). Simultaneously, the same parameters were estimated in maternal capillary blood taken from the arterialized well perfused earlobe. Follicular size was measured by ultrasound. With growing follicular size (FS), the oxygen partial pressure (PO2) fell from 80 to 50-60 mmHg (PO2 = 114.4-3.3.FS; r = 0.79) while the carbondioxide partial pressure (PCO2) in the follicle increased from 35 to 50 mmHg (PCO2 = 15.1 +/- 1.9.FS; r = 0.71). In correlation to these results, the pH in follicular fluid fell from 7.40 to 7.30 (pH = 7.6-0.019.FS; r = 0.62). The correlation between the PCO2 and the pH demonstrates a deviation from the regression line if no metabolic alterations take place (delta log PCO2/delta pH = -0.69). The increase in ovarian blood flow during follicular maturation is obviously not sufficient to bridge the growing diffusion distance between the capillary network surrounding the follicle and its center.(ABSTRACT TRUNCATED AT 250 WORDS)
Assuntos
Líquido Folicular/química , Folículo Ovariano/fisiologia , Oxigênio/análise , Dióxido de Carbono/análise , Feminino , Humanos , Concentração de Íons de Hidrogênio , Pressão ParcialRESUMO
The condition of the fallopian tubes was assessed in 100 fertile women on whom a caesarean section had been performed and in 100 infertile women who had undergone a diagnostic laparascopy. The 100 infertile women revealed both peritubal adhesions (20% vs 2%) and fimbrial agglutinations (4% vs 0%) in a significantly higher number of cases. When the diagnostic procedure was extended to include the salpingoscopy of 20 women with periampullary and peritubal adhesions, 10% of them were found to be suffering from damage of the endosalphinx. In patients with fimbrial agglutination, the same diagnostic procedure revealed mucosal damage in 40% of the cases. The rate of damage to the endosalpinx may help to explain the relatively high rate of ectopic pregnancies (15%) following microsurgical fimbrioplasty. Thus, in cases where the patient is suffering from peritubal adhesions and fimbrial agglutinations, salpinogoscopy can be of use in deciding whether microsurgery is indicated. In those cases, where there is evidence of damage to the endosalpinx, in-vitro fertilization with intrauterine embryo transfer must be considered as the preferential method.
Assuntos
Endoscopia , Doenças das Tubas Uterinas/patologia , Infertilidade Feminina/patologia , Adulto , Diagnóstico Diferencial , Tubas Uterinas/patologia , Feminino , Humanos , Laparoscopia , Aderências TeciduaisRESUMO
The aim of the present investigations was to characterize the endocrine changes in the peripheral plasma during the periparturient phase of mares with a known history of obstetrical disorders. Blood plasma samples from 9 mares (8 mares during parturition, 1 mare during abortion) were collected and the following steroid hormones were radioimmunologically determined: progesterone (P4), dehydroepiandrosterone (DHEA), dehydroepiandrosterone sulfate (DHEA-S), estrone (E1), estrone sulfate (E1-S), estradiol-17 beta (E2), estriol (E3), cortisol and transcortin. In general, with the exception of cortisol, DHEA and transcortin, all steroid hormone levels declined significantly after parturition. Mean plasma concentrations of DHEA-S, the direct fetal precursor of estrone, were 6 times higher than DHEA. However, DHEA-S levels varied considerably between all mares as well as between daily values of the same mare. Levels of E1-S were found to be about thousand times higher than those of E1, E2, and E3. The rather low concentrations of E3 suggest that this hormone is mainly produced by peripheral conversion and that in the horse fetus the 16 alpha-hydroxylation of DHEA-S is lacking. Despite the fact that most of the examined mares showed signs of severe disease none of the investigated steroid hormones indicated any disturbances of gestation. It is concluded that, from the clinical point of view, serial determinations of E1-S plasma levels are the best way to prove the fetal well-being. However, it should be stressed, that even the E1-S values are no indicators for the onset of parturition or abortion.
Assuntos
Aborto Animal/metabolismo , Hormônios/sangue , Doenças dos Cavalos/metabolismo , Complicações do Trabalho de Parto/veterinária , Complicações na Gravidez/veterinária , Animais , Estrogênios/sangue , Feminino , Cavalos , Hidrocortisona/sangue , Complicações do Trabalho de Parto/metabolismo , Gravidez , Complicações na Gravidez/metabolismo , Progesterona/sangue , Esteroide 16-alfa-HidroxilaseRESUMO
Two currently used methods of determining fetal pulmonary maturity were verified on the basis of 148 amniotic fluid samples: one dimensional sequential thin-layer chromatographic determination of the lecithin: sphingomyelin ratio and of phosphatidyl glycerol, and an immunologic slide detection of phosphatidyl glycerol (Amniostat-FLM). With both methods, which have the advantage that they can be performed quickly and can sometimes even be used at the bedside (Amniostat-FLM), a respiratory distress syndrome in the newborn can be ruled out with a high degree of confidence if the threshold values are exceeded (L/S greater than 2; phosphatidyl glycerol present). As with all historical methods, the positive correctness of these two modern methods (no RDS if the child is born within 72 hours despite a negative phosphatidyl glycerol test in the amniotic fluid) is low. Clearly, apart from the quantitative existence of certain surfactant phospholipids (lecithin, phosphatidyl glycerol), there are other perinatal events or measures which determine the extent and severity of RDS in the immature newborn.
Assuntos
Líquido Amniótico/metabolismo , Maturidade dos Órgãos Fetais , Pulmão/embriologia , Fosfolipídeos/metabolismo , Diagnóstico Pré-Natal , Testes de Aglutinação , Amniocentese , Cromatografia em Camada Fina , Feminino , Retardo do Crescimento Fetal/diagnóstico , Humanos , Recém-Nascido , Fosfatidilgliceróis/metabolismo , Gravidez , Síndrome do Desconforto Respiratório do Recém-Nascido/diagnóstico , Fatores de RiscoRESUMO
During opiate anesthesia (standardized dosage of fentanyl) for operation of cerebral aneurysms after subarachnoid hemorrhage, different hemodynamic, respiratory, metabolic, and endocrine parameters were determined before (1 in Fig. 1-4), after (6), and during consecutive stages of induced hypotension (systolic blood pressure 100 mmHg (2), 90 mmHg (3), 80 mmHg (4, 5) during an interval of 20 min), comparing two groups with different vasodilating drugs. In the first group (nimo/NNP in Figs. 2-4) a constant infusion of nimodipine was applied (1.2 micrograms/kg b.w. X min-1), while sodium nitroprusside (NNP) was added in small amounts as necessary to achieve the respective values of systolic blood pressure. In the second group (NNP in Figs. 2-4) induced hypotension was done with NNP alone (maximal dosage: 8 micrograms/kg X min-1). Each group consisted of 11 patients. Additional nimodipine (in the first group), a calcium antagonist commonly recommended for preventing vasospasm and consequent neurologic deficits after subarachnoid hemorrhage, not only reduced the need for NNP, a vasodilating drug with potential toxicity, by 70%-80% as compared to the second group (Table 1). In addition, the cardiovascular situation was more stable in patients with nimodipine infusion: rapid variations of blood pressure and heart rate as well as tachyphylaxis and rebound, typical for NNP-induced hypotension, were avoided. Nevertheless, comparing the hemodynamic data at fixed stages of hypotension, there were only minor differences between both groups (Fig. 2). Reduction of blood pressure was due to a decrease in vascular resistance and was accompanied by an increase in cardiac output.(ABSTRACT TRUNCATED AT 250 WORDS)