Segmental allergen challenge enhances chitinase activity and levels of CCL18 in mild atopic asthma.

BACKGROUND: Allergic airway inflammation contributes to the airway remodelling that has been linked to increased obstruction and morbidity in asthma. However, the mechanisms by which allergens contribute to airway remodelling in humans are not fully established. CCL18, chitotriosidase (CHIT1) and YKL-40 are readily detectable in the lungs and contribute to remodelling in other fibrotic diseases, but their involvement in allergic asthma is unclear. OBJECTIVE: We hypothesized that CCL18, YKL-40 and CHIT1 bioactivity are enhanced in allergic asthma subjects after segmental allergen challenge and are related to increased pro-fibrotic and Th2-associated mediators in the lungs. METHODS: Levels of CCL18 and YKL-40 protein and chitotriosidase (CHIT1) bioactivity in bronchoalveolar lavage (BAL) fluid, as well as CCL18, YKL-40 and CHIT1 mRNA levels in BAL cells were evaluated in patients with asthma at baseline and 48 h after segmental allergen challenge. We also examined the correlation between CCL18 and YKL-40 levels and CHIT1 activity with the levels of other pro-fibrotic factors and chemokines previously shown to be up-regulated after allergen challenge. RESULTS: Chitotriosidase activity and YKL-40 and CCL18 levels were elevated after segmental allergen challenge and these levels correlated with those of other pro-fibrotic factors, T cell chemokines, and inflammatory cells after allergen challenge. CCL18 and YKL-40 mRNA levels also increased in BAL cells after allergen challenge. CONCLUSIONS AND CLINICAL RELEVANCE: Our results suggest that CCL18 and YKL-40 levels and CHIT1 activity are enhanced in allergic airway inflammation and thus may contribute to airway remodelling in asthma.

Transitional hypothermia in preterm newborns.

Hypothermia remains a significant challenge in the initial care of premature infants. Although a number of prevention strategies have been identified, hypothermia is still a common event, especially in extremely low birth weight infants. Using data from four centers, we documented an incidence of hypothermia on admission to the neonatal intensive care unit from the delivery room of 31-78% for infants < 1500 g birth weight. Increased efforts will be necessary to prevent early hypothermia in very preterm infants, especially with respect to the environmental conditions of the delivery room itself. Journal of Perinatology (2007) 27, S45-S47. doi:10.1038/sj.jp.7211842.

Determinants of 25-hydroxyvitamin D levels in African-American and Caucasian male veterans.

SUMMARY: Among 307 males seen in VA Medical Center, independent determinants (p < 0.01 for all) of serum 25-hydroxyvitamin D [25(OH)D] levels included race, vitamin D supplements, BMI, dietary calcium intake and smoking, but not age. Negative association between 25(OH)D and parathyroid hormone (PTH) was similar for Caucasian and African-American men. INTRODUCTION: In this prospective cohort study, we examined determinants of serum 25-hydroxyvitamin D [25(OH)D] levels and the relationship between 25(OH)D and PTH levels and body mass index (BMI). METHODS: Male veterans (n = 307) were recruited at a VA Medical Center. Serum levels of PTH and 25(OH)D were obtained. Surveys and chart reviews were completed. Vitamin D insufficiency was defined as 25(OH)D <30 ng/ml. Univariate and multivariate regression analyses were performed. RESULTS: Among 232 African-American (AA) men (mean +/- SD), 25(OH)D level (21.4 +/- 10.4 ng/ml) was lower and prevalence of insufficiency (80%) was higher than among 75 Caucasians (C; 28.5 +/- 11.1 ng/ml and 53%, respectively, p < 0.01 for both). In multivariate regression analysis, independent determinants (p < 0.01 for all) of 25(OH)D levels included AA race, vitamin D supplements, BMI, dietary calcium intake, and smoking. Despite lower 25(OH)D levels in African-Americans, PTH levels were similar to those seen in Caucasians. There was a significant (p < 0.02) negative linear association between 25(OH)D and PTH in African-American (r(2) = 0.05) and Caucasian (r(2) = 0.08) men, and there was no difference between the slopes of the relationship. CONCLUSIONS: 25(OH)D levels are determined by modifiable risk factors such as vitamin D supplementation in both AA and C males. The negative association between 25(OH)D and PTH is similar between the two races.

Effects of vitamin D insufficiency on bone mineral density in African American men.

UNLABELLED: In African American men serum, 25-hydroxyvitamin D (25-OHD) was below 30 ng/ml in 89% of subjects. In overall group, there was no correlation between 25-OHD and bone mineral density (BMD). A subgroup analysis of subjects with 25-OHD

Antibodies to parathyroid hormone-related protein lower serum calcium in athymic mouse models of malignancy-associated hypercalcemia due to human tumors.

A parathyroid hormone-related protein (PTHrP) has recently been isolated from tumors associated with hypercalcemia. In the present study, we tested the effects of neutralizing antisera to the PTHrP on serum calcium and urine cAMP in two animal models of malignancy-associated hypercalcemia. The animal models consisted of (a) a human squamous cell lung cancer and (b) a human laryngeal cancer, both serially carried in athymic mice. The antisera specifically reduced the elevated serum calcium and urinary cAMP levels in the tumor-bearing animals. We conclude that PTHrP plays a major role in the pathogenesis of malignancy-associated hypercalcemia.

Transitional hypothermia in preterm newborns.

Hypothermia remains a significant challenge in the initial care of premature infants. Although a number of prevention strategies have been identified, hypothermia is still a common event, especially in extremely low birth weight infants. Using data from four centers, we documented an incidence of hypothermia on admission to the neonatal intensive care unit from the delivery room of 31-78% for infants <1500 g birth weight. Increased efforts will be necessary to prevent early hypothermia in very preterm infants, especially with respect to the environmental conditions of the delivery room itself.

The prevalence of emotional abuse in gynaecology patients and its association with gynaecological symptoms.

AIM: To determine the lifetime prevalence of emotional abuse in a population of women attending a gynaecology outpatient clinic and also to investigate whether women who reported emotional abuse were more likely to complain of certain gynaecological symptoms. SETTING: A gynaecology outpatient clinic in a North of England Hospital. METHODS: Anonymous confidential questionnaire given to women. RESULTS: Nine hundred and twenty consecutive women were included, 825 questionnaires were returned (90% response rate). The prevalence of emotional abuse was 24% (198/825). Emotional abuse is four times less common in women over 50 years old. Of the fifteen presenting symptoms reported by the women, referral for termination of pregnancy, cervical smear abnormality, worry about cancer and urinary incontinence were significantly more common in the group who reported emotional abuse. The women with emotional abuse also had significantly more consultations; however, the duration of their symptoms was not significantly different. CONCLUSION: The prevalence of emotional abuse in a group of women attending the gynaecology outpatient clinic in a North of England Hospital was 24%. Women who are subjected to emotional abuse tend to have more consultations and are more likely to complain of certain symptoms.

Transactivation of the PTHrP gene in squamous carcinomas predicts the occurrence of hypercalcemia in athymic mice.

Humoral hypercalcemia of malignancy (HHM) is caused by the secretion of parathyroid hormone-related protein (PTHrP) by tumor cells, and tumors of squamous histology are the ones most commonly complicated by HHM. To determine why some squamous tumors cause HHM and others do not, we quantitated the levels of PTHrP mRNA expression and PTHrP secretion in a series of eight squamous tumor lines. As anticipated, we found that the level of PTHrP mRNA expression in individual lines correlated with their PTHrP secretion rates. However, PTHrP mRNA levels varied widely in individual lines, and only those tumor lines with the highest levels of PTHrP gene expression were able to cause hypercalcemia in athymic mice. We found that a specific segment of the PTHrP promoter could reproduce the relative pattern of PTHrP gene expression when cloned in front of a chloramphenicol acetyltransferase reporter gene and transiently transfected into these squamous lines. Deletional analysis confirmed that specific sequences within the PTHrP gene promoter appeared to be involved in the transactivation of the gene in tumor lines expressing high levels of PTHrP mRNA. These data suggest that the ability of a given squamous tumor to cause HHM is ultimately a function of its level of PTHrP gene expression, which in turn appears to be a function of the ability of specific transcription factors to transactivate PTHrP gene expression.

Splenic sequestration with sickle cell-C disease.

During an episode of pneumonia and multiple pulmonary thromboembolic events, an adult male patient with sickle cell-C hemoglobinopathy developed a severe anemia associated with rapidly increasing splenic size and diminished splenic uptake of technetium Tc 99m sulfur colloid, indicating diminished splenic function due to hypersequestration, a rare and noteworthy phenomenon in adult patients with sickle cell-C disease.

Treatment of cancer-associated hypercalcemia with cisplatin.

Cisplatin (cis-platinum) has been shown to lower cancer-associated humoral hypercalcemia in an animal model and to inhibit bone resorption in vitro. This prospective study was designed to evaluate the efficacy of cisplatin in treating cancer-associated hypercalcemia in humans. Thirteen patients with severe hypercalcemia refractory to rehydration were treated with a 24-hour infusion of cisplatin, 100 mg/m2. Serial measurements of serum calcium and tumor size were made following cisplatin treatment and compared with pretreatment values. Nine patients (69%) achieved normocalcemia after treatment with cisplatin; and mean duration of benefit was 38 days in these patients. No reduction in tumor size was seen. All patients died of progressive cancer. We conclude that cisplatin can control malignant hypercalcemia for relatively long periods, and that its mechanism of action is not due to a reduction in tumor size.

Increased renal calcium reabsorption in an animal model of hypercalcemia of human malignancy.

The present studies examined renal calcium (Ca) clearance in an animal model of malignancy-associated humoral hypercalcemia (MAHH) (a human squamous cell lung carcinoma carried in athymic mice). Three groups of animals--controls, normocalcemic tumor-bearing animals and hypercalcemic tumor-bearing animals--were studied in the basal state and during Ca infusion. Baseline Ca clearance was slightly but significantly elevated in the tumor-bearing hypercalcemic animals compared with the other two groups of animals. This clearance value was, however, inappropriately low for the serum Ca value. In the control and in the normocalcemic tumor-bearing animals, Ca clearance increased markedly during Ca infusion. This increase in renal Ca clearance was markedly blunted in the hypercalcemic animals compared with both the controls and the normocalcemic tumor-bearing animals. We conclude that increased renal Ca resorption contributes significantly to the pathogenesis of hypercalcemia of malignancy.

Effect of epidermal growth factor infusion on serum and urine calcium in mice.

Transforming growth factors (TGFs) have been implicated in the pathogenesis of the hypercalcemia in malignancy (HM). In order to evaluate the role of these growth factors (epidermal growth factor (EGF) and TGF-alpha acting via the EGF receptor) in the development of HM, we studied the effect of 2 doses of EGF (0.1 and 0.3 microgram/g/day) given for 7 days as a continuous infusion on serum and urine calcium in athymic mice. These infusions had no effect on serum and urine Ca values in this study. In order to assess the biological activity of the infused EGF, other known effects on gastric and pancreatic weights were evaluated. EGF-infused animals had significantly greater gastric and pancreatic weights than controls. Thus, EGF infusion into mice in doses which elicited known biological effects failed to have an effect on serum and urine Ca. An infusion of bovine parathyroid hormone 1-34 at the dose of 0.1 microgram/g/day resulted in significant hypercalcemia.

Quantitative bone histomorphometry in nude mice bearing a human squamous cell lung cancer.

We performed quantitative bone histomorphometry on lumbar vertebrae in hypercalcemic tumor-bearing athymic mice carrying a human squamous cell carcinoma. For comparison, studies were also performed in athymic mice that received bovine 1-34 parathyroid hormone (PTH) infusion at the rate of 0.167 micrograms/hr for 7 days. In both the PTH-infused and tumor-bearing animals, percent cortical and total bone areas were significantly reduced as compared to controls, whereas trabecular bone was significantly reduced only in the tumor-bearing animals. Trabecular perimeter lined by osteoclasts was significantly increased in both tumor-bearing (1.7-fold) and PTH-infused animals (2.8-fold) compared to control mice. Trabecular perimeter lined by active osteoblasts was significantly reduced in the tumor-bearing animals (to 42% of control) and unchanged in the PTH-infused animals (97% of control). Tumor-bearing animals had significantly reduced resorptive as well as formative surfaces as compared to the PTH-infused animals. Dynamic histomorphometry revealed a marked reduction in bone formation rate (23% of control) in the tumor-bearing animals. The studies therefore demonstrate a marked inhibition of bone formation associated with increased bone resorption in this model of hypercalcemia of malignancy. These observations are similar to those seen in the human syndrome.

Effects of endurance exercise on bone mass and mechanical properties in intact and ovariectomized rats.

Exercise may play a role in the prevention of bone fractures in postmenopausal osteoporosis. The effects of endurance exercise on bone properties were assessed in 9-month-old sham-operated (SH) and ovariectomized (OVX) rats. The rats were either kept sedentary (SED) or were exercised (EX) on a rodent treadmill at 21 m/minute, 7% grade, 40 minutes/day, 4 days/week for 3 months. Bone mineral (by ash weight), morphometry, and biomechanical properties (by three-point bending) were evaluated after excision of bones at sacrifice. Ovariectomy resulted in a loss of bone mineral in femur, tibia, and fourth lumbar vertebra (L4), but biomechanical (force, deformation, stress, strain, and modulus of elasticity) and morphometric (length, cortical and medullary area, and moment of inertia) properties of femur were maintained. The ash weight of femur and tibia, but not L4, as well as femur yield and maximum force and moment of inertia, were improved in OVX-EX rats compared to OVX-SED animals. In SH rats exercise had no influence on ash weight of any of the three bones or femur morphometric properties, yet femur maximum force and plastic deformation were significantly enhanced compared to SH-SED rats. The results of the present study suggest that endurance exercise has beneficial effects on the bone mineral as well as biomechanical properties (femur yield and maximum force) during early stages after ovariectomy and improves the bending strength of the intact femur without an effect on bone mineral in sham-operated rats.

Effects of cisplatin on parathyroid hormone- and human lung tumor-induced bone resorption.

We have previously shown that dichlorodiamine platinum (DDP), or cisplatin, a cancer chemotherapeutic agent, is effective in the treatment of malignancy-associated hypercalcemia. In the present studies, we evaluated its effects on bovine parathyroid hormone (PTH)- or tumor-induced bone resorption in vitro in the neonatal mouse calvarial bone resorption assay. PTH alone or tumor extract (TE) of a human squamous cell lung cancer alone caused a significant increase in the bone resorption and in the number of osteoclasts in the calvaria. The addition of 3 and 10 micrograms/ml DDP inhibited the PTH- or TE-induced bone resorption. Lower doses of 1 and 2 micrograms/ml DDP, although not effective in inhibiting the PTH-induced bone resorption, were effective in lowering the TE-induced bone resorption. The number of osteoclasts was also reduced by DDP treatment. We therefore conclude that DDP is effective in the treatment of malignancy-associated hypercalcemia by virtue of its inhibitory effects on osteoclast numbers and on bone resorption.

Effects of kistrin on bone resorption in vitro and serum calcium in vivo.

In many cell systems, cell-cell and cell-matrix interactions are mediated by integrins, a family of cell surface heterodimeric glycoprotein receptors. Osteoclast integrins may play a role in the process of bone resorption. Osteoclasts express the alpha v and beta 3 subunits of the vitronectin receptor and adhere to a wide range of proteins in vitro, all which contain the amino acid sequence Arg-Gly-Asp (RGD), an adhesion site recognition sequence common to many protein ligands that bind to integrins. The effect of kistrin, an RGD-containing snake venom protein, on osteoclast-mediated bone resorption was investigated in vivo and in vitro. When kistrin was infused into normocalcemic and hypercalcemic mice, serum calcium was significantly lowered at 3 and 6 h after the start of infusion, indicating an inhibitory effect on osteoclast activity in vivo. In vitro, kistrin potently inhibited bone resorption by isolated rat osteoclasts cultured on slices of bovine bone, and kistrin also inhibited the attachment of 293 cells expressing recombinant human alpha v beta 3 to fibrinogen (IC50 = 1 nM). These results indicate the potential therapeutic use of RGD-containing molecules for hypercalcemia of malignancy or for other disorders associated with bone loss.

Effects of progesterone on postovariectomy bone loss in aged rats.

The effects of progesterone on oophorectomy-induced bone loss in aged rats were evaluated. Female rats aged 12 months were divided into three groups: (1) sham-operated controls (SHAM); (2) oophorectomized (OVX); (3) OVX rats treated with progesterone (OVX + PROG). After 20 weeks the dry weight, bone ash, and calcium content of femur, tibia, and fourth lumbar vertebra were significantly lower in OVX than in sham rats. These reductions did not occur in OVX rats treated with PROG. There was no difference in the bone composition between the control and progesterone-treated rats. Vertebral bone histomorphometry showed increased bone resorption as well as increased bone formation parameters in OVX rats. Progesterone treatment inhibited the increased resorption indices, but the bone formation remained elevated. The results indicate that progesterone therapy prevents the postovariectomy bone loss in aged rats. The protective effect of progesterone is mediated by inhibition of bone resorption while maintaining the increased bone formation. These findings suggest that progesterone alone may be a valuable agent for management of postmenopausal osteoporosis.

Lack of effects of neutralization of parathyroid hormone-related protein on calcium homeostasis in neonatal mice.

Large quantities of parathyroid hormone-related protein (PTHrP) are present in the milk of various species. It has been suggested that PTHrP may play a role in neonatal calcium homeostasis. In the present study we evaluated the effect of neutralization of amino-terminal PTHrP activity by passive immunization in 1-day-old mouse pups. Neutralization of amino-terminal PTHrP activity had no significant effect on serum calcium or whole-body calcium content in the neonatal mice. In additional studies, we demonstrated that subcutaneous administration of PTHrP-(1-34) increased serum calcium, whereas oral administration had no significant effect in 3-day-old pups. The studies therefore demonstrate that the amino terminus of PTHrP may not play a significant role in neonatal calcium homeostasis. Local effects of PTHrP cannot be excluded by the results of the present study.

Effects of progesterone on serum levels of IGF-1 and on femur IGF-1 mRNA in ovariectomized rats.

Local and systemic insulin-like growth factors (IGFs) may be involved in the regulation of bone formation by sex hormones. The present studies describe the in vivo effects of estradiol, progesterone, or both on IGF-1 mRNA abundance in bone, serum IGF-1 levels, and bone formation. Rats were sham-operated (SHAM) or ovariectomized (OVX) at 12 weeks of age and used a week later in three experiments. First, OVX rats were treated with vehicle, estradiol, and/or medroxyprogesterone (MPA) for 3 weeks, and bone formation was assessed in the tibial metaphysis. Second, OVX rats were treated in the same manner and serum IGF-1 levels measured. Third, OVX rats were treated with an injection of vehicle, estradiol, and/or progesterone, and 24 h later, levels of IGF-1 mRNA in the femur were analyzed. The mineralized surface, mineral opposition rate, and bone formation rate (BFR) were higher in OVX than in SHAM rats. The BFR was decreased in estrogen-treated but increased in MPA-treated rats compared with vehicle-treated OVX rats. Circulating levels of IGF-1 were higher in OVX than in SHAM rats but were not affected by sex hormones in a 3-week experiment, whereas these levels were not different among groups in a 24-h experiment. Northern analysis detected 7.5 and 0.8 kb IGF-1 mRNA transcripts. The abundance of IGF-1 mRNA was higher in OVX than in SHAM rats. IGF-1 transcripts 7.5 and 0.8 kb were decreased by 72 and 29%, respectively, in estrogen-treated and increased by 44 and 43%, respectively, in progesterone-treated rats compared with vehicle-treated OVX rats. We conclude that in the short term, estrogen lowers and progesterone raises bone IGF-1 mRNA and these changes are followed by coordinated changes in bone formation rate.

Effect of somatostatin on parathyroid hormone and calcitonin secretion.

This study evaluated the effect of somatostatin on immunoreactive parathyroid hormone (iPTH) and calcitonin (iCT) secretion in vivo in rats and monkeys and on iPTH secretion in vitro by normal bovine parathyroid tissue and by a human parathyroid adenoma. Somatostatin infusion promptly (within 0.5 h) suppressed both iPTH and iCT in both species studied in vivo, the suppression being progressive during the infusion period. In in vitro studies, somatostatin caused significant dose-related decreases in basal, low Ca-stimulated, and high Ca-suppressed PTH secretion from normal bovine parathyroid tissue and from basal and low Ca-stimulated PTH secretion from a human parathyroid adenoma. Therefore, somatostatin 1) suppresses both PTH and CT secretion in vivo; 2) acts directly on the parathyroid cell and presumably directly on the C-cell also; 3) acts upon normal and adenomatous parathyroid tissue; 4) suppresses basal, low Ca-stimulated and high Ca-suppressed PTH secretion; and 5) has a dose-related effect. The possible role of somatostatin in the physiological control of PTH and CT secretion (and therefore in Ca homeostasis), and in the pathogenesis of abnormalities of Ca homeostasis, requires further evaluation.