Impaired lipopolysaccharide-inducible tumor necrosis factor production in vitro by peripheral blood monocytes of patients with viral hepatitis

We investigated lipopolysaccharide-induced tumor necrosis factor production in vitro by peripheral blood monocytes from patients with various liver diseases. Tumor necrosis factor production was found to be significantly reduced in patients with chronic hepatitis B (n = 17; 135 +/- 30 pg tumor necrosis factor/ml; mean +/- S.E.M.) and patients with chronic non-A, non-B hepatitis (n = 15; 212 +/- 22 pg tumor necrosis factor/ml) compared with healthy control individuals (n = 47; 411 +/- 40 pg tumor necrosis factor/ml; p less than 0.0005 and p less than 0.01, respectively). This reduced tumor necrosis factor production was not only seen with an optimal stimulating concentration of lipopolysaccharide (100 ng/ml) but also with suboptimal concentrations (0.1 ng/ml). In contrast to patients with chronic viral hepatitis, monocytes from patients with alcohol-induced cirrhosis (n = 26; 444 +/- 49 pg tumor necrosis factor/ml), primary biliary cirrhosis (n = 7; 412 +/- 81 pg tumor necrosis factor/ml) and alcohol-induced fatty liver changes (n = 5; 401 +/- 62 pg tumor necrosis factor/ml) produced normal amounts of tumor necrosis factor when stimulated with an optimal concentration of lipopolysaccharide. Lipopolysaccharide (0.1 ng lipopolysaccharide/ml)-stimulated peripheral blood monocytes of patients with chronic hepatitis B (n = 15; 102 +/- 32 pg/ml) or non-A, non-B hepatitis (n = 13; 97+/- 16 pg/ml) could not be induced to produce more tumor necrosis factor either when prestimulated with gamma-interferon (170 +/- 45 pg/ml and 149 +/- 32 pg/ml, respectively), a lymphokine known to activate monocytes, or with the cyclooxygenase inhibitor indomethacin to reduce the suppressive effect of prostaglandin E2 (148 +/- 40 pg/ml and 153 +/- 45 pg/ml, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)     

Comparison of the cardiac, renal and endocrine effects of converting enzyme inhibition with those of a classical triple therapy in experimental renal hypertension

In the rat model of hypertension induced by a clip on the right renal artery, sparing the left kidney, we compared the efficacity and the endocrine, renal and cardiac effects of classical therapy (CT) of hypertension (Clonidine 0.2 mg/kg and Dihydralazine 15 mg/kg in 2 daily subcutaneous injections and Furosemide 30 mg/kg/day in the drinking water), with inhibition of the angiotensin converting enzyme with a new drug, the S-9490-3 (0.5 mg/kg in one daily administration). The untreated animals (HT: n = 12) had an average systolic blood pressure (SBP) of 215 +/- 32 mmHg. After 1 month' treatment, S-9490-3 (n = 13) lowers SBP to 144 +/- 32 mmHg compared to CT (n = 12) which lowered SBP to only 172 +/- 18 mmHg. The average plasma renin concentrations of the HT animals was four times the normal value (39 +/- 33 ng/ml/h) and both treatment regimes increased it further (S-9490-3: 129 +/- 65 ng/ml/h; CT: 97 +/- 73 ng/ml/h). Angiotensin levels fell in proportion to the increase in renin concentration. Plasma aldosterone was normalised by S-9490-3 (460 +/- 320 pg/ml) but remained as high after CT (850 +/- 650 pg/ml) as in the untreated HT animals (830 +/- 260 pg/ml). Despite the Furosemide, plasma volume increased significantly in the CT group.(ABSTRACT TRUNCATED AT 250 WORDS)     

Handling during pregnancy in the blue fox (Alopex lagopus): the influence on the fetal pituitary-adrenal axis

Previous studies revealed that handling is a stressor for farmed blue foxes. The present study was designed to examine the effects of a 1-min daily handling stress applied to pregnant blue fox vixens on the function of the fetal pituitary-adrenal system. Plasma concentrations of adrenocorticotropin hormone (ACTH), cortisol, and progesterone, adrenal content of cortisol and progesterone, in vitro adrenal production of these steroids and response to ACTH, and adrenal weights were measured in control (C; n = 73) and stressed (S; n = 58) fetuses. The ACTH levels were lower in stressed fetuses than in the controls (C: males, 128.6 +/- 6.1 pg/ml; females, 165.9 +/- 6.1 pg/ml; S: males, 122.3 +/- 5.4 pg/ml; females, 145.0 +/- 8.1 pg/ml; P < 0.05). In contrast, increased plasma cortisol concentrations in both sexes were demonstrated in stressed compared with control fetuses (C: males, 9.2 +/- 0.4 ng/ml; females, 9.2 +/- 0.4 ng/ml; S: males, 11.8 +/- 0.7 ng/ml; females, 13.2 +/- 0.7 ng/ml; P < 0.00001). The same difference was observed in plasma progesterone concentrations (C: males, 1.54 +/- 0.07 ng/ml; females, 1.49 +/- 0.10 ng/ml; S: males, 1.86 +/- 0.11 ng/ml; females, 1.74 +/- 0.10 ng/ml; P < 0.01). Prenatal stress did not change the baseline adrenal production of cortisol but prevented the cortisol response to ACTH in female fetuses and decreased the progesterone production in both sexes. Additionally, prenatally stressed fetuses of both sexes had significantly lower adrenal weights than controls (C: males, 9.4 +/- 0.3 mg; females, 9.5 +/- 0.4 mg; S: males, 8.1 +/- 0.3 mg; females, 8.2 +/- 0.4 mg; P < 0.001). These results indicate that prenatal handling stress induces a dysregulation of the pituitary-adrenal axis in the fetus and suggest that increased plasma glucocorticoids in the stressed dam can cross the placenta and influence the fetal hypothalamicpituitary-adrenal axis.     

Role of secretory leukocyte protease inhibitor in the development of subclinical emphysema.

Secretory leukocyte protease inhibitor (SLPI) is a potent inhibitor of human leukocyte elastase. In some chronic airway diseases, the level of SLPI is decreased in sputum, leading to the continuation of neutrophil inflammation. In this study, the role of SLPI in subclinical pulmonary emphysema was examined. Sequential bronchoalveolar lavage was performed in an attempt to separately evaluate the levels of SLPI in the large airways and in the peripheral airways for two groups of smokers. One group had subclinical emphysema by computed-tomography scans and one group did not. SLPI localized in alveolar macrophages (AM) was also assessed. The level of SLPI was significantly elevated in the peripheral airways from the subjects with emphysema compared to those without emphysema (1589.2+/-353.9 versus 729.1+/-31.0 ng x mL(-1)), although it was similar in the large airways (3442.3+/-499.6 versus 2535.7+/-578.8 ng x mL(-1)). There was a trend for higher amount of SLPI to be released from AM in subjects with subclinical emphysema, although this did not reach statistical significance. In conclusion, there is compensatory upregulation of secretory leukocyte protease inhibitor in peripheral airways in subclinical pulmonary emphysema, which is in sharp contrast to the decreased level of secretory leukocyte protease inhibitor reported in some chronic airway diseases.     

Pretreatment with ibuprofen augments circulating tumor necrosis factor-alpha, interleukin-6, and elastase during acute endotoxinemia

Plasma levels of tumor necrosis factor-alpha (TNF alpha), interleukin-1 (IL-1), and interleukin-6 (IL-6) were monitored after intravenous administration of Escherichia coli endotoxin with or without ibuprofen pretreatment to healthy volunteers. Intravenous endotoxin (n = 7) resulted in elevated plasma TNF alpha concentrations with maximal levels at 90 min (369 +/- 44 pg/ml, P less than .001 vs. saline controls, n = 7). The rise in TNF-alpha was followed by a rise in plasma IL-6 (27 +/- 12.8 ng/ml), peaking 30-90 min thereafter. Pretreatment with ibuprofen (n = 6) caused a significant augmentation and temporal shift in cytokine elaboration with maximal TNF alpha levels (627 +/- 136 pg/ml) at 120 min and IL-6 peaks (113 +/- 66 ng/ml) at 180 min. In ibuprofen-treated volunteers, the additional increase in TNF alpha was paralleled by increased levels of circulating elastase. In vitro experiments suggest a causal relationship between these events. Thus, the cyclooxygenase inhibitor ibuprofen blunts the clinical response to endotoxin but augments circulating cytokine levels and leukocyte degranulation.     

Degradation of 125I-labelled prolactin in the rabbit: effect of nephrectomy and prolactin infusion

The concentrations of progesterone and oestradiol-17 beta in the maternal plasma of Bennett's wallaby, Macropus rufogriseus rufogriseus, were measured daily throughout gestation after reactivation of the diapausing corpus luteum by removal of the suckling pouch young (RPY). Progesterone increased from mean concentrations of 382-424 pmol/l (120-133 pg/ml) during lactation to reach peak concentrations of 908 +/- 172 (S.E.M.) pmol/l (285 +/- 54 pg/ml) (n = 8) 4 days after RPY and 971 +/- 220 and 971 +/- 229 pmol/l (305 +/- 69 and 305 +/- 72 pg/ml) (n = 7) 24 and 25 days after RPY respectively. The mean gestation length (RPY to birth) was 26.8 +/- 0.6 (S.D.) days (n = 6, range 25.75-27.50 days). Immediately after birth the plasma progesterone concentration declined to 299 +/- 51 (S.E.M.) pmol/l (94 +/- 16 pg/ml) (n = 6). Oestradiol-17 beta increased from mean concentrations of 291-553 pmol/l (80-152 pg/ml) during lactation to reach a peak concentration of 967 +/- 331 pmol/l (266 +/- 91 pg/ml) (n = 9) 1 day after RPY. The concentration declined from 7 days after RPY and fluctuated between mean concentrations of 273 and 480 pmol/l before reaching a minimum of 207 +/- 69 pmol/l (57 +/- 19 pg/ml) (n = 6) 19 days after RPY. A transient increase to 542 +/- 207 pmol/l (n = 7) occurred at 22 days after RPY. Plasma concentrations declined to a low of 156 +/- 55 pmol/l (43 +/- 15 pg/ml) (n = 6) 5 days after parturition. The mean concentration of plasma 13,14-dihydro-15-oxo-prostaglandin F2 alpha was less than 2.8 nmol/l (1 ng/ml) for all samples from 13 days after RPY until 4 days after parturition. The results suggest that oestradiol-17 beta may be important in the early stages of blastocyst reactivation to synergize with progesterone in stimulating uterine secretions. 13,14-Dihydro-15-oxo-prostaglandin F2 alpha is unlikely to be involved in the birth process and any luteolytic effect is likely to be from a local production of PGF2 alpha.     

Acute pulmonary vasoconstriction and thromboxane release during protamine reversal of heparin anticoagulation in awake sheep. Evidence for the role of reactive oxygen metabolites following nonimmunological complement activation

When protamine (2 mg/kg) was injected intravenously into awake sheep 5 minutes after infusing heparin (200 units/kg), there was transient diffuse pulmonary vasoconstriction with mean pulmonary arterial pressure increasing from 18.0 +/- 0.7 to 43.8 +/- 2.7 mm Hg at 1 minute (x +/- SEM; n = 10). In addition, there was profound leukopenia (36.9 +/- 7.7% of baseline values at 2 minutes) with transpulmonary leukocyte sequestration and transiently elevated plasma concentrations of C3a (from 420 +/- 146 to 1,599 +/- 249 ng/ml; n = 3, p less than 0.01) and thromboxane B2 (from 0.30 +/- 0.05 to 6.3 +/- 2.8 ng/ml; n = 10, p less than 0.0001), without significant increases of plasma 6-keto-prostaglandin F1 alpha, prostaglandin F2 alpha, leukotrienes, or histamine. Intravenous injection of protamine alone produced no hemodynamic effects and did not increase plasma levels of vasoconstrictor eicosanoids. Intravenous pretreatment with either a cyclooxygenase inhibitor or a hydrogen peroxide scavenger (dimethylthiourea) blocked both the increases of thromboxane levels and the pulmonary vasoconstriction.     

Selective thromboxane A2 synthetase inhibition in vasospastic angina pectoris

To investigate whether thromboxane A2 is responsible for the initiation of vasospastic angina pectoris, thromboxane B2 levels were measured in the great cardiac vein and the arterial blood of 12 patients with clinically and angiographically proved vasospastic angina and therapeutic trials were performed with selective thromboxane A2 synthetase inhibitor OKY-046, an imidazole derivative. During ergonovine-provoked (11 cases) and spontaneous (1 case) anginal attacks, great cardiac vein thromboxane B2 increased from 121 +/- 27 to 430 +/- 382 pg/ml (p less than 0.05, n = 12), arterial thromboxane B2 increased from 93 +/- 18 to 122 +/- 33 pg/ml (NS, n = 12) and thromboxane B2 production increased from 3.18 +/- 1.88 to 25.16 +/- 22.32 ng/min (p less than 0.05, n = 6). Subsequently, OKY-046, 400 mg/day orally, was administered to 7 of the 12 patients, while a continuous electrocardiogram was recorded on a dual channel Holter monitor during a 3 day placebo period and the 3 day OKY-046 regimen. Although peripheral plasma thromboxane B2 levels decreased significantly from 98 +/- 15 to 12 +/- 8 and 28 +/- 10 pg/ml (1 and 6 hours after ingestion, respectively) (p less than 0.05 for both), 6-keto-prostaglandin F1 alpha production in serum increased significantly from 0.48 +/- 0.22 to 2.3 +/- 0.72 (1 hour) and 1.8 +/- 0.46 ng/ml (6 hours) (p less than 0.05 for both) during OKY-046 administration.(ABSTRACT TRUNCATED AT 250 WORDS)     

Sympathetic nerve stimulation versus pancreatic norepinephrine infusion in the dog: 1). Effects on basal release of insulin and glucagon

We investigated whether pancreatic norepinephrine (NE) infusions could reproduce the inhibition of insulin secretion and the stimulation of glucagon secretion observed during sympathetic nerve stimulation in halothane-anesthetized dogs. Three minutes of stimulating the sympathetic nerves (8 Hz, 1 msec, 10 mA, n = 6) surrounding the pancreatic artery decreased both the blood flow in the superior pancreatic vein (SPV) (delta = -1.7 +/- 0.6 ml/min, P less than 0.05) and the basal pancreatic output of immunoreactive insulin (IRI) (delta = -79 +/- 5%, P less than 0.001). SPV levels of NE increased by 683 +/- 177 pg/ml (P less than 0.02). Infusion of NE into the superior pancreatic artery at the low dose of 12 ng/min (n = 6) reproduced this increase of SPV levels of NE (delta = +740 +/- 130 pg/ml; P less than 0.01) and caused a small reduction of SPV blood flow (delta = -1.0 +/- 0.4 ml/min, P less than 0.05), but did not change pancreatic IRI (delta = -26 +/- 16%, NS). The medium dose of NE (120 ng/min, n = 6) reproduced the nerve stimulation-induced decrease of SPV blood flow (delta = -1.5 +/- 0.2 ml/min; P less than 0.01) and increased the SPV NE levels by 6,306 +/- 1,839 pg/ml (P less than 0.02), yet did not decrease pancreatic IRI output (delta = +62 +/- 49%, NS). The high dose of NE (1,200 ng/min, n = 6) produced an extreme increment of SPV NE levels (delta = +180,000 +/- 44,000 pg/ml, P less than 0.001) and a much larger reduction of SPV blood flow (delta = -3.7 +/- 0.7 ml/min, P less than 0.01) than did nerve stimulation, yet still did not inhibit insulin output (delta = -13 +/- 46%, NS). Ten minutes of sympathetic nerve stimulation increased the pancreatic output of immunoreactive glucagon (IRG) by 1435 +/- 419 pg/min (P less than 0.02). Pancreatic IRG output increased as well during infusion of NE for 10 min at both 12 ng/min (by 575 +/- 205 pg/min, P less than 0.05) and 120 ng/min (by 718 +/- 231 pg/min, P less than 0.05). In marked contrast, during infusion of NE at 1200 ng/min, pancreatic IRG output decreased (by 400 +/- 190 pg/min, P less than 0.05).(ABSTRACT TRUNCATED AT 400 WORDS)     

Modulation of arginine-induced glucagon release by epinephrine and glucose levels in man

To assess how physiological epinephrine (EPI) elevations and EPI-induced hyperglycemia interact in the regulation of glucagon secretion, we measured acute glucagon responses (AGR) to arginine at controlled glucose levels during EPI infusions in man. With glucose levels matched at 166 +/- 5 mg/dl using glucose clamp techniques, the AGR (mean change at 2-5 min) to a 5-g iv arginine injection was greater in each subject during the infusion of 15 ng/kg . min EPI (low EPI) than during the control glucose infusion and was still greater during the infusion of 80 ng/kg . min EPI (high EPI; 69 +/- 15, 76 +/- 13, and 142 +/- 22 pg/ml, respectively; n = 8; P less than 0.003). With glucose levels matched at 256 +/- 5 mg/dl, a similar dose-related enhancement of AGR by EPI was seen (control, 53 +/- 12 pg/ml; low EPI, 63 +/- 5 pg/ml; high EPI, 130 +/- 20 pg/ml; P less than 0.008). During control infusions, raising the glucose level from 102 +/- 2 to 166 +/- 5 to 256 +/- 5 mg/dl suppressed AGR from 77 +/- 17 to 69 +/- 15 to 53 +/- 12 pg/ml (P less than 0.002). During low EPI, the same glycemic increments lowered GR from 108 +/- 19 to 76 +/- 13 to 63 +/- 5 pg/ml (P less than 0.02). This suppression of AGR by hyperglycemia was sufficient to obscure stimulation by EPI: at a glucose level of 102 +/- 2 mg/dl during control infusions, AGR was 77 +/- 17 pg/ml, compared to only 76 +/- 13 pg/ml during low EPI with the glucose level higher (166 +/- 5 mg/dl). Multiple linear regression analysis showed a highly significant dependence of AGR on both EPI and glucose levels, accounting for 80% of the within-subject variation in AGR (P less than 0.0001). These data show that 1) EPI is a dose-dependent amplifier of arginine-induced glucagon secretion in man, and 2) hyperglycemia suppresses arginine-induced glucagon secretion, potentially masking the stimulation caused by EPI. The findings suggest that the feedback effect of hyperglycemia on glucagon secretion may help regulate the level of hyperglycemia resulting from adrenergic stimulation.     

Effects of hyaluronate on CD44 expression of infiltrating cells in exudate of rat air pouch, induced by sensitization with lipopolysaccharide.

OBJECTIVE: To investigate the effects of hyaluronate (HA) on CD44 expression of infiltrating cells in vivo. METHODS: Intra-air pouch injection of 10 microg lipopolysaccharide (LPS) with 0.4, 4.0, or 40 mg HA, 40 mg carboxymethylcellulose (CMC), or saline was performed on rats immunized with LPS. The percentage of CD44+ cells in the exudate of the air pouch was measured by flow cytometry, and the concentrations of interleukin 1beta (IL-1beta) and tumor necrosis factor-alpha (TNF-alpha) in the air pouch exudate were measured by ELISA. IL-1beta and TNF-alpha in the air pouch lining layer were stained by immunohistochemistry. RESULTS: The percentage of CD44+ cells in air pouch exudate was greater in the presence of HA, with a dose dependent increase (0.4 mg, 9.4+/-2.6%, n = 4; 4.0 mg, 13.8+/-2.9%, n = 4; 40 mg, 24.9+/-6.3%, n = 3; p < 0.05), while it was 4.9+/-1.2% (n = 4) in the presence of 40 mg CMC. The concentration of IL-1beta was lower in the presence of 40 mg HA (251.0+/-61.4 pg/ml, n = 4) or 40 mg CMC (168.2+/-43.5 pg/ml, n = 4; p < 0.05) than in saline (403.0+/-60.5 pg/ml, n = 4). The concentration of TNF-alpha was lower in the presence of 40 mg HA (14.0+/-6.7 pg/ml, n = 4) or 40 mg CMC (7.04+/-7.0 pg/ml, n = 4) than in saline (38.2+/-12.2 pg/ml, n = 4). Extensively stained lining cells in superficial layer of the air pouch with IL-1beta and TNF-alpha were observed in rats inoculated with 0.4 mg HA. CONCLUSION: These findings suggest that HA might affect the inflammatory process through modifying CD44 expression on infiltrating cells in air pouch exudate.     

Evidence of hypovitaminosis D in patients with mitral ring calcification

In order to evaluate the role of calcium regulating hormones in the pathogenesis of mitral ring calcification, we have studied the serum levels of PTH and vitamin D metabolites in aged females both with and without mitral ring calcification (MRC). In the patients with MRC (n = 17), significantly lower levels of serum total protein (6.6 +/- 0.2 in the MRC group vs 7.1 +/- 0.1 g/dl in the control group, mean +/- SEM), BUN (15.7 +/- 0.9 vs 18.3 +/- 0.9 mg/dl), creatinine (0.7 +/- 0.02 vs 0.9 +/- 0.02 mg/dl) and calcium (8.4 +/- 0.1 vs 9.2 +/- 0.1 mg/ml) were observed as compared with those in the controls (n = 32). Significantly higher PTH levels (0.57 +/- 0.07 vs 0.38 +/- 0.04 ng/ml) were found in the MRC group. Levels of all three vitamin D metabolites in the MRC group were significantly lower than those in the control group (25-OHD; 11.2 +/- 1.4 vs 19.6 +/- 1.2 ng/ml, 24,25(OH)2D; 0.7 +/- 0.1 vs 1.3 +/- 0.1 ng/ml and 1,25(OH)2D; 12.5 +/- 2.4 vs 43.0 +/- 3.5 pg/ml). The correlation coefficient between PTH and 1,25(OH) 2D was -0.382(n = 49, p less than 0.01). Thus, the significantly higher PTH levels in the MRC group might result in hypovitaminosis D. In conclusion, evidence of hypovitaminosis D in the patients with mitral ring calcification was demonstrated.     

Brain content and plasma concentrations of arginine vasopressin in an Australian marsupial, the brushtail possum Trichosurus vulpecula.

Arginine vasopressin (AVP) has been identified and quantified in the brain and plasma of the possum using a highly specific radioimmunoassay and high-performance liquid chromatography. Large amounts of AVP were found in the pituitary (16.3 +/- 0.56 micrograms/pituitary, n = 5) and hypothalamus (398 +/- 82.5 ng/hypothalamus), and significant amounts of AVP were also present in the cerebral cortex (26.8 +/- 11.5 ng/cortex). Plasma AVP concentrations were significantly lower (2.2 +/- 0.45 pg/ml, n = 10) during anesthesia compared to concentrations while conscious (4.5 +/- 1.19 pg/ml). Severe hemorrhage markedly increased plasma concentrations to 1091 +/- 225 pg/ml (n = 8). It was concluded that AVP is present in the possum brain, pituitary, and plasma, and that its secretion is stimulated by hypovolemia and inhibited by surgical stress.     

The metabolism of prostaglandin E2 by tissues from the human uterus and foeto-placental unit

The biosynthesis and metabolism of prostaglandin E2 was studied in cell-free homogenates of tissues from the uterus and foeto-placental unit using specific in vitro methods. The results show that the synthesis of prostaglandin E2 is greater in endometrial tissue from the secretory phase (53.07 +/- 39.05; ng/100 mg wet tissue/h) than from the proliferative phase of the uterine cycle. Furthermore, endometrial tissue forms more of this compound than myometrium (P less than 0.005). During early pregnancy, synthesis is decreased (25.10 +/- 16.62); at term, myometrium produces more prostaglandin E2 than decidua. During labour, however, decidual tissue accumulates more of this compound (52.73 +/- 18.04) than either myometrium (34.71 +/- 13.19) or cord (28.63 +/- 11.71). The catabolic enzymes are most active in the placenta and chorion, followed by the cord, myometrium, decidua and amnion, but the differences have only a slight effect on the amounts of prostaglandin E2 which remain at the end of the incubation. The results suggest a high turnover of prostaglandin E2 in the decidua, myometrium and cord.     

Activated protein C inhibits local coagulation after intrapulmonary delivery of endotoxin in humans

RATIONALE: Acute lung injury and pneumonia are associated with pulmonary activation of coagulation and suppression of fibrinolysis, resulting in fibrin deposition in the lung. Activated protein C (APC) has systemic anticoagulant effects in patients with sepsis. OBJECTIVE: To determine the effect of systemic administration of recombinant human APC on endotoxin-induced hemostatic alterations in the bronchoalveolar space in humans. METHODS: Healthy humans received intravenous APC (24 microg/kg/hour; n = 8) or vehicle (n = 7); all subjects were administered saline in one lung subsegment and endotoxin (4 ng/kg) into the contralateral lung. Bronchoalveolar lavage was performed 16 hours after saline and endotoxin administration. MEASUREMENTS AND MAIN RESULTS: Endotoxin induced local activation of coagulation, as reflected by elevated levels of thrombin-antithrombin complexes (1.9 +/- 0.1 ng/ml) and soluble tissue factor (15.0 +/- 0.6 pg/ml) in bronchoalveolar lavage fluid, which was inhibited by APC (1.4 +/- 0.1 ng/ml and 12.3 +/- 0.4 pg/ml, respectively; both p < 0.01). Concurrently, endotoxin suppressed fibrinolysis, as indicated by reduced bronchoalveolar levels of plasminogen activator activity accompanied by elevated levels of plasminogen activator inhibitor type I activity. APC diminished the rise in plasminogen activator inhibitor type I activity (from 3.9 +/- 0.1 to 3.0 +/- 0.2 ng/ml, p = 0.002), while not significantly influencing plasminogen activator activity levels. Endotoxin reduced bronchoalveolar protein C concentrations, which was prevented by APC. Protein C did not influence the endotoxin-induced rise in local soluble thrombomodulin levels. CONCLUSION: APC exerts an anticoagulant effect in the human lung challenged with endotoxin.     

Increased plasma immunoreactive neuropeptide Y concentrations in phaeochromocytoma and chronic renal failure

To investigate the clinical usefulness of radio-immunoassay of neuropeptide Y (NPY), we measured plasma immunoreactive neuropeptide Y (IR-NPY) concentrations in normal subjects (n = 21), essential hypertensive patients (n = 33), patients with phaeochromocytoma (n = 7), patients with chronic renal disease with serum creatinine levels of less than 1.9 mg/dl (n = 5) and patients with chronic renal failure whose serum creatinine levels were greater than or equal to 1.9 mg/dl (n = 18, eight without haemodialysis and 10 undergoing maintenance haemodialysis), by radio-immunoassay. Plasma IR-NPY concentrations in patients with phaeochromocytoma (577 +/- 256 pg/ml, mean +/- s.d.) were significantly higher (P less than 0.001) than those in normal subjects (151 +/- 28 pg/ml), essential hypertensive patients (177 +/- 49 pg/ml) and patients with chronic renal disease with serum creatinine levels less than 1.9 mg/dl (198 +/- 71 pg/ml). Plasma IR-NPY concentrations in patients with chronic renal failure (without haemodialysis: 330 +/- 63 pg/ml; undergoing maintenance haemodialysis: 374 +/- 80 pg/ml) were also high. These results suggest that NPY is useful as one of the tumour markers of phaeochromocytomas. However, this study revealed that patients with chronic renal failure, without phaeochromocytoma also have increased plasma IR-NPY concentrations.     

Measurement of betacellulin levels in bovine serum, colostrum and milk

Betacellulin, a member of the epidermal growth factor (EGF) family, was originally isolated and identified from the conditioned medium from a murine pancreatic beta-cell carcinoma cell line. Recently, we isolated bovine betacellulin from a growth factor enriched cheese whey extract, but there is no information on the presence of betacellulin in other biological fluids. We have cloned the cDNA for bovine betacellulin, produced recombinant betacellulin and shown that it has a similar potency to the purified native molecule in stimulating the proliferation of Balb/c3T3 fibroblasts. We have produced a polyclonal antiserum to bovine betacellulin which did not cross-react with EGF or transforming growth factor-alpha (TGF-alpha). The antibody was used in a homologous RIA that was able to detect betacellulin in pooled bovine colostrum sampled during the first 3 days after calving (2.30+/-0.11 ng/ml mean+/-s.e.m.; n=6), in bovine milk soluble fraction (1.93+/-0.64 ng/ml mean+/-s.e.m.; n=5) and in bovine cheese whey (2.59+/-0.16 ng/ml mean+/-s.e.m.; n=3). The betacellulin concentration in foetal bovine serum (FBS) (3.68+/-0.59 ng/ml mean+/-s.e.m.; n=6) greatly exceeded that of betacellulin in serum from male calves 1 and 5 weeks of age (0.53+/-0.15 ng/ml and 0.70+/- 0.09 ng/ml respectively; mean+/-s.e.m.; n=9). Betacellulin measured in the serum of these same animals when aged between 27 and 43 weeks was below the detection limits of the RIA. Sera from 10 out of 36 unmated heifers contained betacellulin levels within the detection limits of the assay (0.433+/-0.06 ng/ml mean+/-s.e.m.; n=10). The presence of betacellulin in bovine colostrum and milk suggests that it plays a role in the growth and development of the neonate and/or mammary gland function. The results also show that betacellulin is undetectable in the castrated adult male circulation. Additionally, although present in very low amounts, serum betacellulin could be under hormonal regulation in the female, since betacellulin was detected in sera from 27% of the unmated heifers examined in this study. The high levels of betacellulin detected in FBS relative to newborn and adult serum suggests a possible endocrine role for this growth factor in the bovine foetus.     

Concentrations of 2-hydroxyoestrogens in human sera measured by a heterologous immunoassay with an 125I-labelled ligand

A heterologous immunoassay for 2-hydroxyoestrogens has been established in which antibodies raised against 2-hydroxyoestradiol-17-succinyl-BSA serve as binding protein and 2-hydroxyoestrone-17-cmo-[125I]iodohistamine as radioligand. Lipophilic serum components competing for binding sites in this system were defined as total 2-hydroxyoestrogens'. The underlying assumption of specificity was supported by the pattern of cross-reactivity evaluated with structural related steroids and o-diphenols and by the fact, that an additional chromatography of the serum extracts preceding the competing reaction had little if any effect. Sensitivity: 2.8 +/- 1 pg/tube; accuracy: Y = 0.91x + 2.2; r = 0.989; precision: 5.8% intra-assay; 6.5% inter-assay. The following concentrations (+/- standard deviation) were found in the sera of healthy subjects. Young men: 29 +/- 5 pg/ml (n = 11); women follicular phase: 32 +/- 8 pg/ml (n = 25); luteal phase: 53 +/- 13 pg/ml (n = 23); postmenopausal women: 13 +/- 4 pg/ml (n = 10); pregnant women 11th--20th week: 70 +/- 16 mg/ml (n = 64); 36th--40th week: 240 +/- 23 pg/ml (n = 40); newborn cord blood: 604 +/- 43 pg/ml (n = 48).     

Interrelation between somatostatin output from the mediobasal hypothalamus and plasma growth hormone levels in conscious rats: effects of glucagon administration

The interrelationship between SRIF output from the mediobasal hypothalamus and plasma GH levels was studied in conscious male rats using the push-pull perfusion technique in combination with repeated blood samplings. The MBH was perfused with artificial cerebrospinal fluid at the rate of 30 microliter/min, and blood samples were collected every 20 min from 1000-1700 h. In control animals, which received injection of acidified saline at 1100 h into the lateral ventricle, two large episodes of spontaneous GH secretion occurred regularly at around 1200 and 1540 h, and troughs occurred around 1400 h. In contrast, SRIF levels from mediobasal hypothalamus perfusate fluctuated at random, ranging from 10-116 pg/ml, with a mean value of 39.2 pg/ml. Mean SRIF levels at 1200 and 1540 h (43.4 +/- 9.0 and 24.4 +/- 4.2 pg/ml, respectively; n = 8) were not different from those at 1400 h (39.9 +/- 12.2 pg/ml). When glucagon (10 micrograms/rat) was injected at 1100 h, plasma GH levels decreased and remained low until 1600 h, whereas perfusate SRIF levels were elevated and remained high for the period. In these animals, the mean plasma GH levels during 1120-1540 h were lower than those in control rats [17.2 +/- 2.4 ng/ml (n = 9) vs. 143.4 +/- 17.5 ng/ml (n = 8); P less than 0.01]. In contrast, the mean SRIF levels in glucagon-treated rats were higher than those in controls [112.5 +/- 15.9 pg/ml (n = 9) vs. control 40.1 +/- 4.3 pg/ml (n = 8); P less than 0.01]. These results suggest that SRIF plays a role in tonic inhibition of GH release in response to the intracerebroventricular injection of glucagon in conscious rats, although SRIF plays, if any, a minor role in regulating episodic GH secretion.     

Evidence that cortisol inhibits basal adrenocorticotropin secretion in the sheep fetus by 0.70 gestation

To ascertain if reductions in fetal plasma cortisol cause increases in fetal plasma ACTH, we treated pregnant ewes or their fetuses with aminoglutethimide (10 mg/kg BW) and metyrapone (20 mg/kg BW) and measured the hormonal responses with RIAs. When given to fetuses (n = 9) at 0.90 +/- 0.01 gestation (term-145 days), the steroid synthesis inhibitors reduced fetal plasma cortisol from 35.1 +/- 11.9 to 18.5 +/- 6.2 ng/ml (P less than 0.01) and plasma ACTH increased from 37 +/- 7 to 189 +/- 74 pg/ml (P less than 0.02). Thus, late in gestation cortisol from the fetal adrenal suppresses basal fetal ACTH secretion. Blockade of steroid biosynthesis in pregnant ewes carrying intact fetuses at 0.76 +/- 0.02 gestation (n = 11) or adrenalectomized fetuses at 0.81 +/- 0.01 gestation (n = 6) also reduced cortisol and increased ACTH in fetal plasma. In intact fetuses cortisol declined from 9.4 +/- 2.0 to 3.6 +/- 0.9 ng/ml (P less than 0.05), and ACTH increased from 46 +/- 8 to 183 +/- 67 (P less than 0.01); cortisol declined in adrenalectomized fetuses from 2.1 +/- 0.4 to 1.1 +/- 0.3 ng/ml (P less than 0.01), and ACTH increased from 106 +/- 13 to 400 +/- 104 pg/ml (P less than 0.01). Cortisol infusions into intact and adrenalectomized fetuses prevented both the decline in steroid concentration caused by the biosynthesis inhibitors given to the ewe and the increase in fetal plasma ACTH concentration. These data indicate that reductions in plasma cortisol in adrenalectomized fetuses or intact fetuses at a time in development when the fetal adrenal produces little cortisol cause compensatory increases in fetal plasma ACTH concentration. The simplest explanation for these observations is that from approximately 0.70 gestation, basal fetal ACTH secretion is tonically inhibited by cortisol circulating in fetal plasma. This cortisol can originate from sources other than the fetal adrenal.