Birger Åstedt

Estrogen receptors in the human female lower urinary tract

Cytosolic and nuclear fractions prepared from the urethra, urinary bladder, and trigonum of the bladder obtained at urethrocystectomy from four female patients were analyzed for the presence of estrogen receptors. High-affinity estradiol receptors (KD 0.7 x 10(-9)M) could be detected in both cytosolic and nuclear fractions of the urethra from all four patients. Estradiol receptors could be detected in only the nuclear fractions of the urinary bladder in two of the four preparations. In the trigonum, cytosolic and nuclear receptors could be measured in one and three preparations, respectively. The receptor concentrations in both trigonum and the bladder were lower than those in the urethra. By providing experimental evidence for the presence of estradiol receptors in the lower uninary tract, the present data advance the case for estradiol therapy in incontinent patients.

Human fetal dopamine neurons grafted in a rat model of Parkinson's disease : immunological aspects, spontaneous and drug-induced behaviour, and dopamine release

SummaryWe have used a rat model of Parkinsons disease (PD) to address issues of importance for a future clinical application of dopamine (DA) neuron grafting in patients with PD. Human mesencephalic DA neurons, obtained from 6.5–8 week old fetuses, were found to survive intracerebral cell suspension xenografting to the striatum of rats immunosup-pressed with Cyclosporin A. The grafts produced an extensive new DA-containing terminal network in the previously denervated caudate-putamen, and they normalized amphetamine-induced, apomorphine-induced and spontaneous motor asymmetry in rats with unilateral lesions of the mesostriatal DA pathway. Grafts from an 11.5-week old donor exhibited a lower survival rate and smaller functional effects. As assessed with the intracerebral dialysis technique the grafted DA neurons were found to restore spontaneous DA release in the reinnervated host striatum to normal levels. The neurons responded with large increases in extracellular striatal DA levels after the intrastriatal administration of the DA-releasing agent d-amphetamine and the DA-reuptake blocker nomifensine, although not to the same extent as seen in striata with an intact mesostriatal DA system. DA fiber outgrowth from the grafts was dependent on the localization of the graft tissue. Thus, grafts located within the striatum gave rise to an extensive axonal network throughout the whole host striatum, whereas grafted DA neurons localized in the neocortex had their outgrowing fibers confined within the grafts themselves. In contrast to the good graft survival and behavioural effects obtained in immunosuppressed rats, there was no survival, or behavioural effects, of human DA neurons implanted in rats that did not receive immunosuppression. In addition, we found that all the graft recipients were immunized, having formed antibodies against antigens present on human T-cells. This supports the notion that the human neurons grafted to the non-immunosuppressed rats underwent immunological rejection. Based on an estimation of the survival rate and extent of fiber outgrowth from the grafted human fetal DA neurons, we suggest that DA neurons that can be obtained from one fetus may be sufficient to restore significant DA neurotransmission unilaterally, in one putamen, in an immunosuppressed PD patient.

Purification of urokinase by affinity chromatography.

Commercially available urokinase (EC 3.4.99.26), though highly active, is still contaminated with unrelated proteins and degradation fragments of urokinase. Further purification of a urokinase preparation by chromatography on benzamidine-Sepharose is described. The final preparation consisted of two molecular forms of urokinase with molecular weights of respectively 31 000 and 54 000. The 54 000-dalton urokinase appears to be composed of two protein chains, one of which is the 31 000-dalton urokinase. A monospecific antiserum against urokinase was raised.

Immunological identity of urokinase and ovarian carcinoma plasminogen activator released in tissue culture.

THERE is evidence that fibrinolytic enzymes are involved in the growth of tumours. It has long been known that malignant tumours in culture lyse clotted plasma substrates1–3. Davidson et al.4 found a giant-cell carcinoma of the lung to be rich in plasminogen activator and to produce it in tissue culture. Rifkin et al.5 reported an abundant release of fibrinolytic enzymes by mammalian fibroblasts transformed by DNA or RNA viruses, by chemically or virally induced mammary carcinomas and by human malignant tumours in culture. Normal fibroblasts and cultures of other normal tissues released little or no fibrinolytic enzymes. Christman and Acs6 found neoplastic cells, whether transformed by oncogenic viruses or by chemical agents, to release a plasminogen activator not released by normal cells. This activator was characterised as a serine protease with a molecular weight of approximately 50,000. The presence of fibrinolytic activity has been demonstrated in human ovarian tumours7 as well as in ascitic fluid associated with such tumours8. We have studied a stable plasminogen-activating enzyme, released by ovarian carcinoma in tissue culture, and we report here the apparent identity of this plasminogen activator (TA) and the activator produced by foetal kidney and present in normal urine—that is, urokinase.

Isolation of a new specific plasminogen activator in hibitor from pregnancy plasma

Summary. A specific plasminogen activator inhibitor was isolated from the plasma of pregnant women by matrix‐bound, cross reacting monoclonal antibodies against placental plasminogen activator inhibitor. The pregnancy plasma plasminogen activator inhibitor (PP‐PA‐I) was found to be immunologically different from the inhibitor produced by endothelial cells. Its molecular weight was 70 000 daltons. It formed complexes with urokinase (u‐PA) and with plasminogen activator of the tissue type (t‐PA), similar to those formed by the placental plasminogen activator inhibitor (Pl‐PA‐I). It did not inhibit plasmin. For measuring PP‐PA‐I, an enzyme‐linked immunosorbent assay (ELISA) was designed using monoclonal and polyclonal antibodies against the placental inhibitor. Concentrations of PP‐PA‐I increased successively during pregnancy, and fell sharply after delivery. This inhibitor could not be detected in normal non‐pregnancy plasma. The results indicate that the inhibitor isolated from pregnancy plasma is responsible for the depressed fibrinolytic activity during pregnancy, and that the placenta is the source of the inhibitor.

Tissue plasminogen activator and plasminogen activator inhibitor-1 in stroke patients

BACKGROUND AND PURPOSE Abnormal endogenous fibrinolytic activity may be a risk factor for stroke. Since the possible variation of tissue-type plasminogen activator (TPA) antigen and plasminogen activator inhibitor-1 (PAI-1) antigen concentrations over time after stroke has been rarely studied, it was examined in plasma from stroke patients in the acute and convalescent phases of the disease and in a control group. METHODS Plasma concentrations of TPA and PAI-1 were determined in 135 stroke patients and in 77 control subjects. All but 4 patients were examined within 7 days after stroke onset, and 32 patients and 18 control subjects were reexamined 2 to 4 years later. RESULTS In the acute phase, stroke patients had significantly higher TPA (median, 10 micrograms/L) and PAI-1 (median, 14 micrograms/L) antigen concentrations, compared with control subjects (median values, 6 micrograms/L [P = .0001] and 8 micrograms/L [P < .01], respectively); TPA levels were higher in both the cerebral infarction (n = 122) and cerebral hemorrhage (n = 12) subgroups, whereas PAI-1 levels were higher in the cerebral infarction subgroup only. Stepwise logistic regression analysis (with correction for age, sex, history of hypertension, diabetes mellitus, and heart disease) showed TPA antigen level to be an independent discriminator between the cerebral infarction subgroup and control subjects (P = .0001), whereas the corresponding difference for PAI-1 antigen levels just failed to reach significance (P = .05). TPA antigen levels were correlated with concentrations of serum cholesterol (Spearmans rho = 0.15; P < .05), serum triglyceride (rho = 0.33; P = .0001), and plasma homocysteine (rho = 0.19; P < .01). PAI-1 antigen levels were correlated with serum triglyceride levels only (rho = 0.41; P = .0001). At reexamination after 2 to 4 years, neither TPA nor PAI-1 levels had changed significantly from the baseline values. CONCLUSIONS In stroke patients, high TPA antigen concentrations may indicate an activation of the fibrinolytic system or may be due to a delayed clearance of TPA complexed with inhibitors. High PAI-1 antigen concentrations in patients with cerebral infarction represent increased fibrinolytic inhibition. The findings in this longitudinal study suggest that TPA and PAI-1 antigen concentrations both differ little between the acute and convalescent phases after stroke.

An inhibitor from placenta specifically binds urokinase and inhibits plasminogen activator released from ovarian carcinoma in tissue culture.

An inhibitor present in placenta and released in placental tissue culture forms specific complexes with each of two molecular forms of urokinase. Autoradiography demonstrated that the inhibitor shifted the electrophoretic position of 125I-labelled urokinase. It did not change the migration of diisopropyl-fluorophosphate-inactivated 125I-labelled urokinase, thereby indicating complex formation dependent on active serine site in urokinase. The inhibitor had a strong neutralizing effect on the plasminogen activators released from human ovarian carcinoma in tissue culture. The placental inhibitor might prove useful in inhibiting the fibrinolytic process necessary for proliferation of tumour vessels.

Preeclampsia is associated with a reduced response to activated protein C

OBJECTIVE Resistance to activated protein C is an inherited mutation of the coagulation factor V gene, a major factor predisposing to thromboembolic events. The purpose of this study was to investigate the occurrence of heterozygote and homozygote activated protein C resistance in women with preeclampsia. STUDY DESIGN Activated protein C resistance and protein C and antithrombin III levels were determined in women (n = 50) with a history of preeclampsia and in controls (50 women with a previous normal pregnancy). The mutation of the factor V gene was analyzed. RESULTS Activated protein C resistance was found in 22% of women with previous preeclampsia compared with 10% among controls. Two women in the previous preeclampsia group had a homozygote mutation of factor V; the others were heterozygous. There was a significant difference in the activated protein C ratio between women with previous preeclampsia and the control group, 2.6 +/- 0.4 versus 3.1 +/- 0.5 (p = 0.04). None of the women had protein C or antithrombin III deficiency. CONCLUSION The results indicate that activated protein C resistance may be a contributory factor in the pathogenesis of preeclampsia.

On some Late Effects of Bilateral Oophorectomy in the Age Range 15–30 Years

Abstract. Between 1910 and 1940, 146 young females, aged 15–30 years, underwent bilateral salpingo‐oophorectomy as part of a radical operation for salpingo‐oophoritis. These women or their records were reviewed in 1971. 42 women had died in the meantime. More than half (22) of them had died from cardiovascular diseases, 5 from carcinoma of the uterus and 4 had committed suicide. None had died from carcinoma of the breast. Of 68 who were still alive, information by questionnaire was obtained and 32 were admitted to hospital for extensive examination. 32 age‐matched women to be operated on for prolapse but with no other known disease of the reproductive tract served as controls. A further control group was added as 11 of the 68 were found to have menstruated again after the operation which had evidently not completely removed the gonads. Complete oophorectomy was found to have been followed by: (a) an increased incidence of cardiac symptoms and nervous diseases as well as an increased use of drugs; (b) a significant increase in the frequency of coronary vascular diseases in ages up to 70 years; (c) an increase in the serum cholesterol and triglycerides, most significantly in the ages below 60‐65 years. Women with symptomatic coronary disease had a higher serum cholesterol level than women without and women with signs of peripheral vascular diseases had a significantly higher concentration of serum triglycerides: (d) an increased frequency of fractures (radius and femoral neck), increased osteoporosis and thinner cortical bone. The brittleness of the skeleton was correlated with low excretion of oestrogens in the urine. No vertebral compression or abnormal decrease in height was observed, (e) an increased adrenocortical activity with significantly increased excretion of 17‐ketosteroids, 17‐OH‐ketosteroids and low polar total oestrogens. This activity abated in women above 65 years. (f) a traumatic psychological experience of the accompanying sterility while sexuality seemed to be largely unaffected in many of them. Almost half of the women examined by the psychiatrist were unusually mentally active and agile and they had a lower excretion of estriol than the rest.

Transdermal estrogen replacement therapy: beneficial effects on hemostatic risk factors for cardiovascular disease

OBJECTIVES To assess the effect of estrogen replacement therapy on hemostatic risk factors for cardiovascular disease (CVD) in postmenopausal women during 2 years of treatment. METHODS In an open prospective study, patients (n = 42) were investigated before and during 2 years of treatment, and compared to an untreated postmenopausal control group (n = 18) followed during the same period, healthy premenopausal women (n = 20) being included as a reference group for premenopausal values. The patients underwent treatment with transdermal 17 beta-estradiol (E2) (50 micrograms/24 h), oral medroxyprogesterone acetate (5 mg/day) being added for 12 days every second month. RESULTS After 2 years of treatment there was a significant increase in t-PA antigen (P = 0.01) and a significant decrease in F VII antigen (P = 0.01). PAI-1 antigen concentrations decreased slightly. Fibrinogen concentrations were already significantly decreased at 3-month follow-up (P = 0.01), and were still low after 2 years. By contrast, at 2-year follow-up the postmenopausal control group manifested significant increases in F VII and PAI-1 antigen and slight increases in fibrinogen, which resulted in significant differences between patients and controls. Regression analysis showed the increase in the serum estradiol concentrations to be inversely correlated to the decreases in the plasma concentrations of F VII antigen (r = -0.34, P = 0.001) and fibrinogen (r = -0.35, P = 0.001). There were no changes in AT III or protein C in any group. CONCLUSIONS The increase in serum estradiol concentrations due to replacement therapy did not adversely affect the studied components of the fibrinolytic and protein C defense system against thrombosis, and resulted in beneficial decreases in F VII antigen and fibrinogen. These findings may help to explain the beneficial effects of estrogen replacement therapy in terms of protection from cardiovascular disease.