Effects of arginine-vasopressin and parathyroid hormone-related protein (1-34) on cell proliferation and production of YKL-40 in cultured chondrocytes from patients with rheumatoid arthritis and osteoarthritis.

OBJECTIVE: Both arg-vasopressin (AVP) and parathyroid hormone-related protein (PTHrP) may act as proinflammatory hormones. In addition, they have been suggested to be involved in the pathophysiology of rheumatoid arthritis (RA). We therefore investigated the effects of AVP and PTHrP (1-34) on cell proliferation and secretion of the glycoprotein YKL-40 in human chondrocytes derived from healthy subjects as well as from patients with RA or osteoarthritis (OA). METHOD: Primary cultures of human chondrocytes were incubated with AVP (1-100 pmol/l) or PTHrP (1-34) (0.1-100 nmol/l). Cell proliferation was measured as [3H]thymidine incorporation. Intracellular cAMP and YKL-40 in cell medium were determined by commercially available kits. RESULTS: AVP and PTHrP (1-34) increased proliferation in chondrocytes derived from healthy donors as well as from RA and OA patients. PTHrP (1-34), but not AVP, increased intracellular levels of cAMP. PTHrP (1-34) did not change the amount of YKL-40 in chondrocytes from healthy subjects or patients with OA. AVP tended to decrease the secretion of YKL-40 from healthy chondrocytes. Both PTHrP (1-34) and AVP increased YKL-40 secretion from RA chondrocytes. In contrast, AVP decreased the secretion of YKL-40 in chondrocytes from patients with OA. CONCLUSION: AVP and PTHrP (1-34) stimulated proliferation in human chondrocytes derived from healthy subjects as well as from patients with RA or OA. However, the effects of AVP and PTHrP (1-34) on YKL-40 secretion varied depending on the origin of the chondrocytes.

Osteoblast dysfunction in male idiopathic osteoporosis.

The etiology of primary osteoporosis in young and middle-aged men is unknown. We have studied osteoblast function in cells derived from men with idiopathic osteoporosis and in control cells from age-matched men with osteoarthrosis. Osteoblasts were isolated from transiliac bone biopsies. Osteoblast function was measured as vitamin D-stimulated osteocalcin production and production of cytokines and factors involved in osteoclast activation and bone formation. Cell proliferation was measured as (3)H-thymidine incorporation. Parathyroid hormone-related peptide (PTHrP) mRNA was measured using reverse-transcriptase polymerase chain reaction. In osteoporotic men, bone mineral density at the femoral neck was correlated to in vitro production of osteocalcin. Osteoblasts from osteoporotic men produced significantly less osteocalcin after vitamin D stimulation but had increased production of macrophage colony-stimulating factor (M-CSF) compared to controls. The osteocalcin response was negatively correlated to production of M-CSF, interleukin-6, and C-terminal propeptide of type I collagen. Basal (3)H-thymidine incorporation was similar in cells from osteoporotic patients and controls. PTHrP (10(-9 )M) significantly increased cell proliferation in control cells but not in osteoporotic cells. Basal PTHrP mRNA levels were significantly higher in osteoporotic cells than in cells from controls. The results are in agreement with previous histomorphologic studies indicating that men with idiopathic osteoporosis have an osteoblast dysfunction with decreased osteocalcin production and increased production of factors stimulating osteoclast activation. This indicates a catabolic cellular metabolic balance leading to negative bone turnover, resulting in osteoporosis. The cause of such cellular dysfunction needs further evaluation.

Parathyroid hormone-related protein in patients with primary breast cancer and eucalcemia.

Parathyroid hormone-related protein (PTHrP) is a causative factor of humoral hypercalcemia in breast cancer and other malignancies. We studied circulating PTHrP levels with three different immunoassays directed against different parts of the PTHrP molecule in 48 patients with breast cancer and eucalcemia. The methods used were: (a) a RIA with antibodies directed toward the midregion (63-78); (b) an immunofluorometric assay with two antibodies against 1-34 and 38-67; and (c) an immunoradiometric assay with antibodies against 1-40 and 1-72. Although most patients had PTHrP levels indistinguishable from normal when measured by all three methods, four patients had increased serum levels in the IFMA. PTHrP was detected by immunohistochemistry in tumors from nearly all patients. One patient with elevated PTHrP in plasma measured by IFMA showed intense staining of tumor by immunohistochemistry; the tumor was histologically graded as III (severe) and was the largest of all tumors in this patient group. The IFMA can identify increased serum PTHrP in some patients with breast cancer who are not hypercalcemic. This assay may be especially useful in screening patients for this tumor during a relative early phase of the disease.

Effect of acute endurance and strength exercise on circulating calcium-regulating hormones and bone markers in young healthy males.

Physical activity plays a role in the maintenance of the skeleton but the mechanical, metabolic and hormonal mechanisms involved are largely unknown. The influence of acute endurance and strength exercise on circulating levels of calcitonin, parathyroid hormone (PTH), PTH-related peptide (PTHrP), osteocalcin, carboxyterminal cross-linked telopeptide of type I collagen (ICTP) and ionized calcium (Ca2+) was therefore evaluated. Eight healthy young males performed three exercise bouts on separate occasions: endurance exercise, i.e. cycling on a cycle ergometer for 45 min at 55% of Vo2max (E55%) and 15 min at 85% of Vo2max (E85%) and strength exercise at 85% of three repetitions maximum using a leg-press device (STR). Control experiments included the same subjects with the same time schedule but without exercise. Blood samples were taken before, immediately after exercise and during the recovery period. Hormones and bone markers were measured by use of various immunoassays. There was no obvious influence on calcitonin and PTHrP levels, whereas PTH was increased after strength exercise. ICTP and osteocalcin levels correlated positively at all times and showed regular variations. In comparison with the controls, ICTP levels showed a more pronounced decrease following physical activity whereas osteocalcin followed the same pattern as the controls except for after prolonged endurance exercise when a decrease was abolished. In conclusion, an increase in PTH after strength exercise and a pronounced decrease in ICTP after all exercise together with a relative increase in osteocalcin after prolonged endurance exercise might reflect some mechanisms involved in the positive effect of physical activity on bone mass.

Midmolecular parathyroid hormone-related peptide in serum during pregnancy, lactation and in umbilical cord blood.

Indications of an important physiological role of parathyroid hormone-related peptide (PTHrP) for fetal calcium homeostasis, maternal-fetal calcium transport and reproduction have accumulated over recent years. The PTHrP concentrations were measured by an earlier developed midregion radio-immunoassay in serum from lactating healthy females and umbilical cord blood and compared with levels in age-matched non-pregnant or lactating females. The PTHrP concentrations could be measured in all samples after silica cartridge C18 extraction of 10-12 ml of serum. The concentrations were significantly higher during lactation (mean +/- SD: 0.72 +/- 0.14 pmol/l, N = 22) and in umbilical cord blood (0.85 +/- 0.18 pmol/l, N = 12) compared with healthy age-matched women (0.48 +/- 0.09 pmol/l, N = 10, p < 0.001). The molecular forms of PTHrP were also studied in an age-matched control group, in pregnant women and in umbilical cord blood by gel chromatography in a fast protein liquid chromatography system of Sep-Pak-extracted pooled serum. In all three groups we found heterogeneity of the molecular forms with two predominant peaks. The smallest fragment had a molecular weight of 4-6 kD while the largest form appeared as a high-molecular-weight molecule. In conclusion, the concentrations of midmolecule PTHrP fragments in serum are elevated during lactation and in umbilical cord blood. Because the midregion of PTHrP has unique actions, our results indicate that PTHrP may play an important physiological role for the mother and for the maternal-fetal calcium transport.

Serum calcitonin forms and concentrations in young and elderly healthy females.

To further investigate the role of calcitonin (CT) in normal physiology we studied circulating forms and the secretion after "calcium clamp" in young and elderly healthy females. Heterogeneity of CT in serum was disclosed after immunoextraction, fast protein liquid chromatography, and radioimmunoassay in young (27 +/- 3 years; mean +/- SD, n = 6) and elderly females (69 +/- 6 years, n = 11). Three distinct molecular forms appeared with approximate mol wt of 30, 10, and 3-4 kDa. All young women studied had considerable amounts of circulating monomer-like CT whereas several elderly had undetectable or low levels. The influence of age on basal and calcium stimulated, immunoextracted CT in serum was also studied in young (26 +/- 4 years; mean +/- SD, n = 13) and elderly (63 +/- 6 years; n = 12) healthy females. The calcium stimulation was carried out by means of the standardized calcium clamp method, where calcium was kept on a presettled level at 1.45 mmol/liter (+/- 2%) for 60 minutes. CT was immunoextracted from serum in all series of experiments with a polyclonal antiserum directed against the mid- and carboxyterminal region of the CT molecule, and the amount of extracted CT was determined by radioimmunoassay using another polyclonal antiserum against the carboxyterminal portion. After calcium infusion, the increase in CT was significantly higher in young women than in elderly (P < 0.05). At basal conditions, the CT levels were not significantly different but slightly higher in young than in elderly females. In conclusion, several elderly women lack monomer-like calcitonin in serum in contrast to young women.(ABSTRACT TRUNCATED AT 250 WORDS)

Parathyroid hormone-related peptide, measured by a midmolecule radioimmunoassay, in various hypercalcaemic and normocalcaemic conditions.

The diagnosis of humoral hypercalcaemia of malignancy often presents considerable clinical problems. We have studied parathyroid hormone-related peptide (PTHrP) in serum from patients with humoral hypercalcaemia of malignancy (N = 22), hypercalcaemia of malignancy with skeletal metastases (17), histologically confirmed primary hyperparathyroidism (21) and hypercalcaemic patients with various benign diseases (9). PTHrP measurements were also made in normocalcaemic patients with various malignancies (23), endocrine diseases (13), sarcoidosis (22) and chronic renal failure (17). PTHrP was measured by a novel radioimmunoassay using rabbit antibodies directed towards the midregion of the molecule. Immuno- or silica cartridge extraction of serum before radioimmunoassay enabled us to measure PTHrP in all samples, which may add further information about circulating forms of PTHrP. PTHrP was clearly elevated in patients with humoral hypercalcaemia of malignancy (5.0 +/- 4.7 pmol/l) (mean +/- SD, N = 12) and when the kidney function was impaired (4.0 +/- 0.9 pmol/l) (N = 15) (silica cartridge extraction), whether the subject was hypercalcaemic or not. Some patients with endocrine diseases, including two with primary hyperparathyroidism, had slightly elevated serum PTHrP concentrations, while they were normal in sarcoidosis. In healthy subjects the levels were 1.1 +/- 0.5 pmol/l (N = 15) after immunoextraction and 0.8 +/- 0.2 pmol/l (N = 33) after silica cartridge extraction.

A rapid extraction method for serum calcitonin.

A rapid, simple and reliable extraction method for calcitonin from serum has been developed. 2 volumes of acidic ethanol and 1 volume of serum were mixed, centrifuged, and the supernatant was evaporated to dryness. The extracts were reconstituted in assay buffer before radioimmunoassay was performed. Basal concentrations of calcitonin after extraction were 5.4 +/- 3.0 pg-equivalents/ml (mean +/- SD), females, n = 48 and 8.8 +/- 5.5 pg-equivalents/ml, males, n = 42. Calcitonin was detectable in serum from all males and from 90% of the females. The concentrations in males were significantly higher (P less than 0.001). There was a more pronounced calcitonin response in males (n = 12) than in females (n = 12) to a calcium clamp (P less than 0.01). Gel chromatography of serum from patients with medullary thyroid carcinoma on a Sephadex G-75 column and a TSK G 2000 SW column in a fast protein liquid chromatography system, disclosed that the ethanol extraction excluded the high mol mass forms of calcitonin. We propose the acidic ethanol extraction as a convenient method for routine measurements of calcitonin.

Postmenopausal osteoporosis: response of immunoextracted calcitonin to a calcium clamp.

Fourteen postmenopausal females with osteoporosis (PMO) and 14 healthy postmenopausal females (PMF) were studied by means of the calcium clamp-technique. Plasma was collected before start and during the 1 hour calcium clamp. Calcitonin (CT) was immunoextracted from plasma with antiserum No. 1 directed against the mid- and carboxyterminal portion of CT. Thereafter radioimmunoassay was performed on the extracts with antiserum No. 2 directed against the carboxyterminal of CT. The detection limit of the assay was 0.8 pg/tube. There was no difference between patients and controls in the basal CT values and CT was detectable in all samples after immunoextraction. Plasma CT increased significantly during the calcium clamp in osteoporotic patients as well as in controls and the CT response did not differ between the groups. The results do not support the hypothesis of a diminished CT secretion as a contributing factor to the development of osteoporosis.

Immunoextracted calcitonin in human gastric secretion.

Immunoreactive calcitonin (iCT) has been demonstrated in human gastric juice after immunoextraction with immobilized antibodies and subsequent radioimmunoassay. The basal levels were 4.5 +/- 3.1 (mean +/- SD) pg-Eq/ml gastric juice; range 1.2-9.1 pg-Eq/ml; n = 7, and after stimulatory gastric secretion test with pentagastrin 0.3 +/- 0.2 pg-Eq/ml; range 0.1-0.7 pg-Eq/ml; n = 7 (p less than 0.01). The main fraction of iCT from gastric juice eluted in the same region as synthetic human calcitonin (hCT) on Sephadex G-75 gel chromatography. Reverse phase chromatography in a fast protein liquid chromatography (FPLC) system revealed a slightly less hydrophobic character of the iCT from gastric juice compared to synthetic monomeric hCT. The results were further confirmed by using an additional antiserum. In plasma, the calcitonin (CT) levels were after immunoextraction at the basal state 6.6 +/- 1.7 pg-Eq/ml (mean +/- SD); range 5.1-10.1 pg-Eq/ml; n = 7 and after pentagastrin stimulation 9.4 +/- 5.4 pg-Eq/ml; range 6.3-18.5 pg-Eq/ml; n = 7.

A search for gender differences on fertility-related attitudes: questioning the relevance of sociobiology theory for understanding social psychological aspects of human reproduction.

PIP: Data drawn from 12 representative sample surveys of the US adult population conducted by the National Opinion Research Council in 1965-84 were used to test the hypothesis that men and women would have different attitudinal orientations toward fertility. This hypothesis was suggested by the sociobiological theory that anatomic differences between the sexes outweigh those imposed by socialization. Specifically, it was postulated that women will consider a smaller number of children as ideal and will be more approving of abortion than men because of women's greater concern with the quality rather than quantity of offspring. The data failed to support this hypothesis. In 16 of 20 comparisons, there were no significant differences between men and women in terms of average number of children considered ideal or approval of abortion. In the remaining 4 comparisons, men were slightly more approving of legalized abortion and women preferred a slightly higher family size. Gender never explained as much as 1% of the variance in either attitude variable, and education and religiosity correlated consistently more strongly with ideal family size than did gender. These findings cast doubt on a theoretical approach that asserts the dominance of biologic causation over social forces.^ieng

Mental status outcomes following carotid endarterectomy: a six-month analysis.

Fifty-one male and two female patients were divided into the following three groups: (a) patients with symptomatic carotid artery disease who received carotid endarterectomies, (b) patients with symptomatic carotid artery disease who either declined or were not candidates for carotid endarterectomies, and (c) patients who received a surgical procedure unrelated to cerebral functioning. The three groups were not significantly different in terms of age or educational level. The subjects were examined using the WAIS, Wechsler Memory Scale, Halstead-Reitan Neuropsychological Battery, Sickness Impact Profile, and Profile of Mood States. The assessments were conducted presurgery and repeated at a 6 month follow-up. The results of two-way analyses of variance revealed a significant trials effect for a majority of the variables, including the average impairment rating and the full scale WAIS IQ. However, significant group x trials interactions were not found for either the neuropsychological measures or the quality of life indices. The results did not support the conclusion of improved mental status or increased psychosocial well-being in patients who received carotid endarterectomies.

Abortion attitudes, 1965-1980: trends and determinants.

PIP: Results of surveys sponsored by the National Opinion Research Center between 1965 and 1980 show that approval of abortion increased from an average of 41% for 6 different reasons in 1965 to 68% in 1973, with levels remaining stable through 1977, decreasing to an average of 64% in 1978, and rebounding to the 1973-77 level in 1980. 7% of respondents disapproved of abortion for all 6 of the stated reasons, which ranged from endangerment of the woman's health through a married woman wanting no more children. More than half of those approving of abortion do not do so for all reasons, with approval ranging from 90% if the woman's health is endangered to 47% if the women is married and wants no more children. Multiple regression analysis of the independent effect of 8 types of factors on abortion attitudes, by themselves and in combination, was conducted. Those favoring and opposing legal abortion do not differ on 11 of 13 values ascribed to child development, but differ on obedience and curiosity, suggesting a more authoritarian attitude toward childrearing and less emphasis on children's self-reliance among abortion opponents. Education has the strongest effect of the various social and demographic variables examined, with the better educated more likely to favor abortion availability, except among Catholics. Approval of abortion decreases with conservatism regarding various aspects of personal morality. The strongest negative relationship occurs with disapproval of premarital sex and preference for large numbers of children. Political party and ideology are only weakly linked to legal abortion approval. Approval of abortion increases with support for women's rights and basic civil liberties.^ieng