Effects of growth hormone replacement therapy on 1,25-dihydroxyvitamin D and calcium metabolism

To elucidate the changes in mineral metabolism and blood concentrations of calciotropic hormones which accompany GH therapy, we studied 12 GH-deficient children for 5 days before and for 1 week after high dose (5 IU/day) GH therapy, and again at 1 month, 3 months, and 1 yr of replacement therapy (0.1 IU/kg to a maximum dose of 2 IU three times weekly). All responded with acceleration of height velocity, and bone ages advanced appropriately. Fasting serum ionized calcium levels did not change: 4.11 +/- 0.06 (SEM) mg/dl before, 4.19 +/- 0.05 for the week of high dose therapy, and 4.20 +/- 0.14 during replacement therapy. Likewise, fasting serum parthormone did not vary: 38.9 +/- 2.6 muleq/ml before to 44.1 +/- 9.2 at 1 yr. Twenty four-hour nephrogenous cyclic AMP (NcAMP) did not vary over the first week (1.2 +/- 0.7 nmol/dl glomerular filtrate before, 1.3 +/- 0.4 after 1 week), but increased to 5.3 +/- 1.9 after 1 yr (alpha less than 0.001). The response of ionized calcium and parathormone to a standardized disodium EDTA infusion of 50 mg/kg also did not change. The mean fasting serum calcitonin level was not different before therapy (29.4 +/- 2.8 pg/ml), after 1 week (21.5 +/- 1.8), or after 1 yr (42.4 +/- 11.0). However, the mean serum 1,25-dihydroxyvitamin D concentration rose from 33.1 +/- 3.3 pg/ml before therapy to 68.3 +/- 12.3 on the seventh day of high dose therapy (alpha less than 0.01), returning to pretherapy values by 1 month. We conclude that high dose GH therapy in GH-deficient children raises 1,25-dihydroxyvitamin D concentration acutely, but that long term, physiological replacement therapy does not cause such an effect. Because NcAMP excretion rose in the absence of an increase in serum parathormone concentration, we conclude that GH sensitizes the kidney to a cAMP-mediated effect of parathormone.     

The role of allogeneic bone marrow transplantation in adult patients below the age of 55 years with acute lymphoblastic leukemia in first complete remission: a donor vs no donor comparison

The role of allogeneic bone marrow transplantation (alloBMT) in adults with acute lymphoblastic leukemia (ALL) in first complete remission (CR1) remains controversial. At our institution, the policy is to offer alloBMT to ALL patients in CR1 up to the age of 55 years if a related donor is available. In addition, unrelated donor transplants are offered to patients with Philadelphia (Ph+) ALL. We report the results on 92 patients with ALL treated according to this policy from September 1992 to October 2001. Of the 87 patients achieving CR1, the comparison of patients with (n=48) or without donors (n=39) was done using an intention-to-treat approach. Of the 48 patients with donors (39 related and nine unrelated), 35 (73%) received alloBMT in CR1. No significant difference in 3-year event-free survival (EFS) (40 vs 39%, P=0.74) or overall survival (OS) (46 vs 58%, P=0.41) was seen in 'donor' vs 'no-donor' groups. For Ph+ patients, 3-year EFS and OS in 'donor' group were 46 and 57%, respectively, none of the patients in 'no-donor' group survived beyond 3 years. With our treatment strategy, 3-year OS of Ph+ patients was equivalent to Ph-negative (Ph-) patients (51 vs 52%, P=0.77). In conclusion, our data show that the policy of performing alloBMT if a sibling donor is available has not resulted in better outcome in Ph- patients.     

Characterization of the human neutrophil C1q receptor and functional effects of free ligand on activated neutrophils

The partial characterization and expression of the C1q receptor (C1q-R) in relation to other complement receptors present on the surface of neutrophils has been examined, as well as the effects of free C1q on cell function. A polyclonal anti-C1q-R antibody recognizes a 68-kD neutrophil surface protein. C1q-R expression was not upregulated upon warming, priming, or exposure to FMLP, but decreased after exposure to phorbol myristate acetate (PMA), because of shedding of the receptor into the extracellular medium, as detected by enzyme-linked immunosorbent assay. CR3 and CR1 expression was upregulated from intracellular pools after cell stimulation by PMA. No evidence of intracellular pools of C1q-R was found, as assessed by immunoblotting of subcellular fractions. But C1q-R appeared to be expressed early in cell differentiation, was detected on undifferentiated HL-60 cells, and like CR3 expression, increased upon 5 days differentiation towards a neutrophil lineage. However, C1q-R expression decreased upon additional culture, whereas CR3 expression continued to increase. A large variation in the percentage of peripheral cells expressing C1q receptors in donors was observed, ranging from 13% to 100%, contrasting with CR3 receptors that exhibited less variability. Interactions between free monomeric C1q and neutrophils were also studied. Incubation of stimulated neutrophils with 10 to 100 micrograms/mL C1q resulted in a further increase in CR3 expression and adherence to albumin-coated surfaces. Staphylococci opsonized with low quantities of C1q (0.1 to 1 microgram/mL) mediated a moderate and sustained respiratory burst in neutrophils, whereas a burst of similar magnitude was generated only with free C1q at concentrations 10- to 100-fold higher. Stimulation was only partially inhibited if cells were first treated with anti-C1q-R antibody, suggesting other C1q binding proteins may be present on the cell surface. In summary, neutrophil C1q receptor is approximately 68-kD, exhibits varying expression on different subjects, and is not upregulated from intracellular stores on exposure to soluble stimuli. Stimulated, but not resting, neutrophils selectively respond to raised levels of free C1q, resulting in altered cell function and enhanced CR3 receptor expression. These studies thus suggest complex roles for C1q in neutrophil function.     

Generation of CD1+RelB+ dendritic cells and tartrate-resistant acid phosphatase-positive osteoclast-like multinucleated giant cells from human monocytes

We previously showed that granulocyte-macrophage colony-stimulating factor (GM-CSF) and macrophage colony-stimulating factor (M-CSF) stimulate the differentiation of human monocytes into two phenotypically distinct types of macrophages. However, in vivo, not only CSF but also many other cytokines are produced under various conditions. Those cytokines may modulate the differentiation of monocytes by CSFs. In the present study, we showed that CD14+ adherent human monocytes can differentiate into CD1+relB+ dendritic cells (DC) by the combination of GM-CSF plus interleukin-4 (IL-4) and that they differentiate into tartrate-resistant acid phosphatase (TRAP)-positive osteoclast-like multinucleated giant cells (MGC) by the combination of M-CSF plus IL-4. However, the monocyte-derived DC were not terminally differentiated cells; they could still convert to macrophages in response to M-CSF. Tumor necrosis factor-alpha (TNF-alpha) stimulated the terminal differentiation of the DC by downregulating the expression of the M-CSF receptor, cfms mRNA, and aborting the potential to convert to macrophages. In contrast to IL-4, interferon-gamma (IFN-gamma) had no demonstrable effect on the differentiation of monocytes. Rather, IFN- gamma antagonized the effect of IL-4 and suppressed the DC and MGC formation induced by GM-CSF + IL-4 and M-CSF + IL-4, respectively. Taken together, these results provide a new aspect to our knowledge of monocyte differentiation and provide evidence that human monocytes are flexible in their differentiation potential and are precursors not only of macrophages but also of CD1+relB+DC and TRAP-positive MGC. Such a diverse pathway of monocyte differentiation may constitute one of the basic mechanisms of immune regulation.     

Clinical impact of functional testing strategy among stented and non-stented patients: insights from the ROSETTA Registry

The clinical utility of routine functional testing following percutaneous coronary intervention (PCI) among patients with and without coronary stenting is unclear. We established an international registry to evaluate the functional testing strategies following successful PCI. Among patients treated with stents, adverse cardiovascular outcomes were similar between those who underwent routine or clinically-driven functional testing. Conversely, among those who were not treated with stents, the rate of death, myocardial infarction or unstable angina was lower than those who underwent routine functional testing (14.8% vs. 6.6%; P=0.033). Our study suggests that routine functional testing may be beneficial to patients not treated with stents. BACKGROUND: The role of routine functional testing following successful PCI is unclear. By improving patient outcomes with coronary stenting, the value of such a strategy may diminish. HYPOTHESIS: To determine the clinical utility of routine functional testing following PCI between patients with and without stenting. METHODS: The routine versus selective exercise testing after angioplasty (ROSETTA) Registry was established to evaluate the utilization of functional testing following PCI. Use of functional testing, either routine or selective (clinically-driven), was left to the discretion of the attending physician. RESULTS: Of 791 patients enrolled, 462 (58%) underwent coronary stenting. Stented patients were less likely to suffer from concomitant diseases but had more complex angiographic morphological characteristics. Between the groups of patients with and without stents, there was no difference in the proportion of patients undergoing routine functional testing (24% vs. 36%) or subsequent cardiac procedures (18.4% vs. 16.0%). Among patients with stents, outcomes at 6 months were similar between the groups undergoing routine and selective functional testing, including death (0% vs. 1.7%), myocardial infarction (0.9% vs. 2.0%), unstable angina (9.9% vs. 13.7%), repeat angiography (16.2% vs. 16.9%) and revascularization procedures (11.7% vs. 10.8%). However, among non-stented patients, selective functional testing was associated with a higher occurrence of death, myocardial infarction or unstable angina (14.8% vs. 6.6%; P=0.033). There was also no difference in the rates of repeat coronary angiography or revascularization procedures between these two strategies. CONCLUSION: Although routine functional testing has little impact on outcomes among patients treated with coronary stents, non-stented patients may derive particular benefit.     

Effects of erythromycin on Pseudomonas aeruginosa adherence to collagen and morphology in vitro.

The airways of patients with bronchiectasis and cystic fibrosis are often chronically colonised by Pseudomonas aeruginosa (PA), which is virtually impossible to eradicate. Low-dose erythromycin (EM), for unknown mechanisms, is efficacious in bronchiectasis and diffuse panbronchiolitis. In this study, an in vitro model to investigate PA adherence to human type IV basement collagen was developed by using scanning electron microscopy (SEM). There were significantly less PA bacilli per 20 random SEM fields (4,000x) when PA was cultured in 0.05, 0.5 and 5 microg x mL(-1) of EM compared with control (absence of EM). Adherence density (20 SEM fields x log(-1) inocular size) for PA obtained from no EM (56.8 +/- 43.16) was significantly higher than that obtained from 0.05, 0.5, and 5 microg x mL(-1) EM (21.5 +/- 17.56, 23.3 +/- 16.65, and 21.4 +/- 12.65 respectively). By using SEM it was found that PA, when incubated in EM (0.05, 0.5, 5 microg x mL(-1)) had a significant reduction in its diagonal length, radius, height, volume and surface area. It is possible, therefore, that these misshaped Pseudomonas aeruginosa bacilli are more susceptible to host defence mechanisms, while at the same time less adherent to the basement membrane of the airway in vivo. Therefore, this could help explain the clinical efficacy of low-dose erythromycin therapy on patients with Pseudomonas aeoruginosa infection.     

Improvement of barrier function and stimulation of colonic epithelial anion secretion by Menoease Pills

AIM: Menoease Pills(MP)1 a Chinese medicine-based new formula for postmenopausal women, has been shown to modulate the endocrine and immune systems. The present study investigated the effects of MP and one of its active ingredients, ligustrazine, on epithelial barrier and ion transport function in a human colonic cell line, T84.METHODS: Colonic transepithelial electrophysiological characteristics and colonic anion secretion were studied using the short circuit current (Isc) technique. RT-PCR was used to examine the expression of cytoplasmic proteins associated with the tight junctions, ZO-l(zonula occludens-1) and ZO-2 (zonula occludens-2).RESULTS: Pretreatment of T84 cells with MP (15 μg/mL) for 72 h significantly increased basal potential difference,transepithelial resistance and basal ISC. RT-PCR results showed that the expressions of ZO-land ZO-2 were significantly increased after MP treatment, consistent with improved epithelial barrier function. Results of acute stimulation showed that apical addition of MP produced a concentrationdependent (10-5 000 μg/mL, EC50 = 293.9 μg/mL) increase in ISC. MP-induced ISC was inhibited by basolateral treatment with bumetanide (100 μmol/L), an inhibitor of the Na^+-K^+-2Cl^- cotransporter, apical addition of Cl^- channel blockers, diphenylamine-2, 2‘-dicarboxylic acid (1mmol/L) or glibenclamide (1 retool/L), but not 4, 4‘-diisothiocyanostilbene-2, 2‘-disulfonic acid or epithelial Na+ channel blocker,amiloride. The effect of MP on ZOo1 and ZO-2was mimicked by Ligustrazine and the ligustrazine-induced ISC was also blocked by basolateral application of bumetanide and apical addition of diphenylamine-2, 2‘-dicarboxylic acid or glibenclamide, and reduced by a removal of extracellular Cl^-.CONCLUSION: The results of the present study suggest that MP and lligustrazine may improve epithelial barrier function and exert a stimulatory effect on colonic anion secretion, indicating the potential use of MP and its active ingredients for improvement of GI tract host defense and alleviation of constipation often seen in the elderly.