[Efficacy of non-surgical comprehensive treatment for locally advanced hypopharyngeal carcinoma with cervical esophagus invasion].

Objective: To analyze the treatment effects and side effects of non-surgical comprehensive treatment for locally advanced hypopharyngeal carcinoma invading cervical esophagus. Methods: A retrospective analysis was performed on sixty-six patients with locally advanced hypopharyngeal carcinoma invade the esophagus. These patients were treated in the Department of Otolaryngology, Head and Neck Surgery of Chinese People's Liberation Army General Hospital between January 2011 and May 2022, including sixty-five males and one female, aged 43-71 years. Treatment regimen consisted of induction chemotherapy and concurrent chemoradiothrapy and epidermal growth factor receptor (EGFR)-targeted therapy, three of these cases were treated with programmed cell death 1 (PD-1) immunotherapy. The Kaplan-Meier method was used for survival analysis. Side effects were evaluated with the established CTCAE (Common Terminology Criteria for Adverse Events) 5.0 criteria. The factors affecting prognosis were analyzed by Cox multivariate regression analysis. Results: Sixty-four (97.0%, 64/66) patients completed the radiotherapy and chemotherapy plan. The most common grade three side effects were radioactive oropharyngeal mucositis (89.1%, 57/64) and leukopenia (23.4%, 15/64). Five (7.8%, 5/64) patients showed grade three hoarseness; two patients (3.1%, 2/64) suffered from grade three swallowing dysfunction and required feeding tube and intravenous nutrition; the remaining patients(89.1%) retained good vocal and swallowing functions. The overall survival (OS) of all patients was 81.5% after one year, 54.0% after three years, and 39.9% after five years; the progression-free survival (PFS) was 78.3% after one year, 54.9% after three years, and 42.6% after five years; local control rate (LCR) was 80.9% after one year, 62.5% after three years, and 52.0% after five years. T4a patients showed better OS, PFS and LCR than T4b patients, with statistically significant differences (χ2=8.10, 8.27, and 6.64, respectively, all P<0.05). Cox multivariate regression analysis showed that lymph node metastasis was an independent factor affecting prognosis (χ2=10.21, P<0.05). Conclusion: Non-surgical comprehensive treatment can provide with another option of radical treatment for locally advanced hypopharyngeal carcinoma with cervical esophagus invasion, offering the patients higher rate of larynx and esophageal preservation with tolerable side effects.

[Retrospective analysis on 77 cases of T4b hypopharyngeal carcinoma treated by non-surgical treatments].

Objective: To analyze the effectiveness, safety and factors influencing the clinical prognosis of patients with hypopharyngeal carcinoma in T4b by nonsurgical treatments. Methods: The clinical data of 77 patients with T4b hypopharyngeal cancer treated in the College of Otolaryngology Head and Neck Surgery of the Chinese People's Liberation Army General Hospital from January 2010 to June 2021 were analyzed retrospectively. All were males, aged(57.0±8.0)years old. Patients were treated with induction chemotherapy plus concurrent chemoradiotherapy. Kaplan Meier survival analysis was used to compare the effects of different factors on prognosis. Adverse reactions during treatments and the causes of death were analyzed. Results: 98.7% of 77 patients with T4b hypopharyngeal cancer completed the chemotherapy plan and 94.8% completed the radiotherapy plan. The most common adverse reactions were grade 2 radiation oral mucositis (50/77, 64.9%) and grade 2 leukopenia (50/77, 64.9%). The incidence of grade 3 severe hoarseness was 7.8% (6/77), one patient (1.3%) underwent gastrostomy due to dysphagia, and pronunciation and swallowing function were effectively preserved in other patients. The overall survival rate was 71.9% at 1 year, 45.6% at 3 years and 29.7% at 5 years. The location of tumor, the presence of liquefaction necrosis in tumor, the use of molecular targeted drugs and the approach of radiotherapy were independent factors,each of which that affected the prognosis of T4b patients with advanced hypopharyngeal cancer [HR (95%CI) were 1.867(1.085-3.213), 3.018 (1.437-6.335), 0.372 (0.181-0.764) and 2.158 (1.015-4.588), respectively, P<0.05]. The two leading causes of death with high incidence were disease recurrence (12/32, 37.5%) and cervical large vessel rupture and hemorrhage (11/32, 34.4%). Conclusions: Non-surgical comprehensive treatment offers a high laryngeal preservation rate in patients with T4b hypopharyngeal cancer. The location of tumor, the liquefaction necrosis within tumor, the use of molecular targeted drugs, and the approach of radiotherapy are independent prognostic factors.

[Relationship of quality and duration of sleep with hypertension among adults in Guangzhou].

Objective: To explore the relationship of sleep quality and sleep duration with hypertension among adults aged 30-79 years old in Guangzhou. Methods: According to multi-stage stratified cluster sampling, 12 747 residents aged 30-79 years old were sampled and surveyed in Guangzhou from January 2018 to March 2019. Data on general demographic characteristics, sleep quality, sleep duration and hypertension were collected through questionnaire survey, the Pittsburgh sleep quality index (PSQI) and physical examination. Multivariate logistic regression models were used to analyze the putative association between sleep quality, sleep duration and hypertension. Restrictive cubic spline curve was used to draw the dose-response relationship curve between sleep quality, sleep time and hypertension. Results: The mean age of the subjects was (52.68±12.17) years, the prevalence of hypertension was 36.6% (4 664/12 747), the average score of PSQI was (4.70±2.88), and the average sleep time was (7.00±1.32) hours. The prevalence of hypertension was positively associated with the PSQI score. Compared to the subjects with a score less than 3, OR (95%CI) of hypertension with a PSQI score of 3-5, 5-8, ≥9 were 1.14 (1.02-1.27), 1.17 (1.03-1.34), 1.41 (1.21-1.64), respectively. The relationship between sleep duration and hypertension appeared U-shaped. Compared with 6 to 8 hours sleep duration, both sleep duration<6 hours with OR(95%CI) of 1.27(1.12-1.43) or >8 hours with OR(95%CI) of 1.20(1.05-1.38) was associated with hypertension. Conclusion: Both poor sleep quality, longer or shorter sleep duration were responsible for increased risk of cognitive impairment in older Chinese.

Effects of treadmill running in a rat model of chronic kidney disease.

Chronic kidney disease (CKD) progression results in musculoskeletal dysfunction that is associated with a higher likelihood of hospitalization and is predictive of hospitalizations and mortality. Despite this, there is a lack of effective interventions to treat the musculoskeletal dysfunction. We studied treadmill running as an intervention to improve musculoskeletal health in a translational rat model that has slowly progressive CKD. CKD rats were subjected to treadmill exercise or no treadmill exercise for 10 weeks (n = 8 each group). Animals ran for 60 min, 5 times per week starting at a speed of 8 m/min and ending at 18 m/min (1 m/min increase/week). Treadmill training had no effect on muscle strength (assessed as maximally stimulated torque), half-relaxation time (time from peak torque to 50%) or muscle cross-sectional area. Overall, there were no biochemical improvements related to CKD progression. Skeletal muscle catabolism was higher than non-exercised animals without a concomitant change in muscle synthesis markers or regeneration transcription factors. These results suggest that aerobic exercise, achieved via treadmill running was not protective in CKD animals and actually produced potentially harmful effects (increased catabolism). Given the high prevalence and dramatic musculoskeletal mobility impairment in patients with CKD, there is a clear need to understand how to effectively prescribe exercise in order to benefit the musculoskeletal system.

[Clinical analysis of multimodal treatment for orbital organ preservation in T4b squamous cell carcinoma of nasal cavity and paranasal sinuses].

OBJECTIVE: To investigate the efficacy of induction chemotherapy (ICT) followed by concurrent chemotherapy and helical tomotherapy (HT) in the patients with T4b squamous cell carcinoma of nasal cavity and paranasal sinus (SCCNP) for orbital organ preservation and high quality of life. METHODS: A total of 26 patients with the orbital involvement of T4b SCCNP between May 2008 and March 2013 were analyzed retrospectively. There were 17 males and 9 females; the average age was 54.7 years. The median follow-up time was 25 months (range 4-77 months). The patients received 1-2 cycles ICT with TP (docetaxel 70 mg/m(2) on day 1 and cisplatin 40 mg/m(2) on day 1-2, every 3 weeks) or TPF (docetaxel 70 mg/m(2) on day 1 and cisplatin 70 mg/m(2) on day 1-2, 5-fu 700 mg/m(2) on day 1-5, every 3 weeks), followed by concurrent HT (60-70 Gy) and chemotherapy with TP and/or epidermal growth factor receptor (EGFR) inhibitor. The Kaplan-Meier method was used to determine the 3-year overall survival rate and local control rate. Side-effects were evaluated with the established common terminology criteria for adverse events (CTCAE) version 4.0 criteria. RESULTS: All patients completed the planned chemotherapy and 96.2%(25/26)patients completed the planned radiotherapy. The 3-year overall survival rate, the local control rate and real orbital preservation rate were 56.7%, 79.5% and 80.0% respectively. The most common acute side effects higher than grade 2 were oral mucositis, radiodermatitis and dry eye syndrome. CONCLUSION: The strategy including ICT followed by CCRT and/or EGFR inhibitor is an effective treatment for T4b SCCNP patients, with minimal toxicities, higher 3-year OS rate and orbital preservation rate, and also provides a new treatment option for T4b SCCNP patients.

Analysis of cell cycle shortening and developmental interruption in Dictyostelium discoideum allC RNAi mutants.

Dictyostelium discoideum allC RNAi mutant cells are motile and aggregate together, but do not undergo further morphological development. The relatively quick growth rate of allC RNAi mutants compared to wild-type D. discoideum results in a shortened mutant cell cycle. However, at present, little is known about the mechanism underlying this phenomenon. Here, we used semi-quantitative reverse transcription-polymerase chain reaction (RT-PCR), real-time quantitative RT-PCR, two-dimensional gel electrophoresis, and mass spectrometry/mass spectrometry to elucidate the phenomenon. We found significant downregulation of myosin II heavy chain, D. discoideum calcium-dependent cell adhesion molecule-1 (DdCAD-1) mRNA, DdCAD-1 protein, D. discoideum mRNA for 14-3-3 and 14-3-3 protein, and type A von Willebrand factor domain-containing protein mRNA in allC RNAi mutants. The results suggest that downregulation of the myosin II heavy chain could be one of key factors causing the developmental interruption and that downregulation of the 14-3-3 protein and the type A von Willebrand factor domain-containing protein mRNA plays an important role in shortening the cell cycle of allC RNAi mutants.

Skeletal effects of zoledronic acid in an animal model of chronic kidney disease.

UNLABELLED: Bisphosphonates reduce skeletal loss and fracture risk, but their use has been limited in patients with chronic kidney disease. This study shows skeletal benefits of zoledronic acid in an animal model of chronic kidney disease. INTRODUCTION: Bisphosphonates are routinely used to reduce fractures but limited data exists concerning their efficacy in non-dialysis chronic kidney disease. The goal of this study was to test the hypothesis that zoledronic acid produces similar skeletal effects in normal animals and those with kidney disease. METHODS: At 25 weeks of age, normal rats were treated with a single dose of saline vehicle or 100 µg/kg of zoledronic acid while animals with kidney disease (approximately 30% of normal kidney function) were treated with vehicle, low dose (20 µg/kg), or high dose (100 µg/kg) zoledronic acid, or calcium gluconate (3% in the drinking water). Skeletal properties were assessed 5 weeks later using micro-computed tomography, dynamic histomorphometry, and mechanical testing. RESULTS: Animals with kidney disease had significantly higher trabecular bone remodeling compared to normal animals. Zoledronic acid significantly suppressed remodeling in both normal and diseased animals yet the remodeling response to zoledronic acid was no different in normal and animals with kidney disease. Animals with kidney disease had significantly lower cortical bone biomechanical properties; these were partially normalized by treatment. CONCLUSIONS: Based on these results, we conclude that zoledronic acid produces similar amounts of remodeling suppression in animals with high turnover kidney disease as it does in normal animals, and has positive effects on select biomechanical properties that are similar in normal animals and those with chronic kidney disease.

Theoretical study of (Ag,Au and Cu)/Al(2)O(3) interfaces.

Interface structure is a basic problem in interface and surface science. It is usually indicated by atomic positions for an ideal interface. But this way is sometimes unsuitable for a mismatch interface, because there are too many atoms under consideration, whose coordinates may confuse our mind in understanding the interface structure. In this case, a 'dislocation representation' is introduced. A misfit dislocation network is used as an effective representation of the interface structure. However, there are two questions on this topic. How to determine the dislocation network structure? And how to relate it to interface dynamics? In this paper, we work on the first question and make an effort to build up the 'dislocation representation' for metal/Al(2)O(3) interfaces.

The mechanisms of uremic serum-induced expression of bone matrix proteins in bovine vascular smooth muscle cells.

We have previously found that uremic human serum upregulates RUNX2 in vascular smooth muscle cells (VSMCs), and that RUNX2 is upregulated in areas of vascular calcification in vivo. To confirm the role of RUNX2, we transiently transfected a dominant-negative RUNX2 (DeltaRUNX2) construct in bovine vascular smooth muscle cells (BVSMCs). Blocking RUNX2 transcriptional activity significantly decreased uremic serum induced alkaline phosphatase (ALP) activity (268+/-34 vs 188+/-9.5 U/g protein, P<0.05) and osteocalcin expression (172+/-17 vs 125+/-9 ODU, P<0.05). To determine the mechanism by which uremic serum upregulates RUNX2, we examined cell signaling pathways. BVSMCs were incubated in the presence or absence of inhibitors and RUNX2 expression and ALP activity were determined. The results demonstrate that the cyclic AMP (cAMP)/protein kinase A (PKA), but not protein kinase C, signaling pathway is involved in uremic serum-induced RUNX2 expression and ALP activity in BVSMCs. To examine potential uremic 'toxins', we measured bone morphogenetic protein (BMP)-2 concentration and found that uremic serum contained increased BMP-2 (uremic serum=169+/-33 pg/ml, normal serum=117+/-15 pg/ml, P<0.05). The incubation of BVSMCs with noggin, an inhibitor of BMP, decreased RUNX2 expression. In addition, BMP-2 secretion progressively increased during calcification and uremic serum enhanced its secretion compared to normal serum. In conclusion, this study demonstrates that RUNX2 transcriptional activity is critical in uremic serum-induced bone matrix protein expression in BVSMCs and that the cAMP/PKA pathway is involved. BMP-2 is also increased in uremic serum and can upregulate RUNX2 and calcification in vitro in VSMCs.

Cluster expansion of electronic excitations: application to fcc Ni-Al alloys.

The cluster expansion method is applied to electronic excitations and a set of effective cluster densities of states (ECDOS) is defined, analogous to effective cluster interactions (ECIs). The ECDOSs are used to generate alloy thermodynamic properties as well as the equation of state (EOS) of electronic excitations for the fcc Ni-Al systems. When parent clusters have a small size, the convergence of the expansion is not so good but the electronic density of state (DOS) is well reproduced. However, the integrals of the DOS such as the cluster expanded free energy, entropy, and internal energy associated with electronic excitations are well described at the level of the tetrahedron-octahedron cluster approximation, indicating that the ECDOS is applicable to produce electronic ECIs for cluster variation method (CVM) or Monte Carlo calculations. On the other hand, the Gruneisen parameter, calculated with first-principles methods, is no longer a constant and implies that the whole DOS profile should be considered for EOS of electronic excitations, where ECDOS adapts very well for disordered alloys and solid solutions.

S-nitrosoglutathione inhibits TNF-alpha-induced NFkappaB activation in neutrophils.

OBJECTIVE AND DESIGN: Cytokine expression is controlled by transcription factors including NFkappaB, which has recently been found to exist in human neutrophils. We previously showed that exogenous nitric oxide (NO) induces neutrophil apoptosis and hypothesized that this NO effect could be mediated by inhibition of NFkappaB activation. MATERIALS AND METHODS: Isolated human neutrophils were incubated with or without S-nitrosoglutathione (GSNO 0.1 mM-5 mM; Sigma) for 2 h. Neutrophils were either unstimulated or stimulated with TNFalphalpha or n-formyl methionyl leucine phenylalanine (fMLP). Viability was assessed by vital dye cytotoxicity assay. After nuclear extraction and measurement of protein concentration, NFkappaB binding was determined by electrophoretic mobility shift assay. Effects of GSNO on activation of IkappaB alpha, which inhibits intranuclear translocation of NFkappaB, were measured by Western immunoblot technique. For comparison, experiments were also performed in the presence of the NFkappaB inhibitor PDTC. RESULTS: TNFalpha increased nuclear NFkappaB activity compared to unstimulated neutrophils (p < 0.001, n = 5). GSNO (500 microM) decreased TNFalpha-induced NFkappaB activity (p<0.05) and inhibited NFkappaB activity whether given prior to or during TNFalpha exposure. IkappaB alpha was significantly degraded at 30 and 120 min of TNFalpha exposure compared to control neutrophils (p < 0.05). GSNO exposure (500 microM) inhibited IkappaB alpha degradation in the presence of TNFalpha. PDTC enhanced neutrophil cell death and DNA fragmentation, in association with decreased NFkappaB activity, similar to GSNO effects. CONCLUSION: Neutrophils possess NFkappaB activity that is increased by stimulation with TNFalpha. GSNO inhibits NFkappaB activity in association with inhibiting TNFalpha-induced degradation of IkappaB alpha. GSNO effects are similar to those seen with NFkappaB inhibition by PDTC. Inhibition of NF kappaB could represent a potential anti-inflammatory effect of GSNO.

The role of the synovium and cartilage in the pathogenesis of beta(2)-microglobulin amyloidosis.

The predilection for beta(2)-microglobulin (beta(2)M) amyloid deposition in articular structures is unique compared to other forms of amyloid; this article focuses on possible pathogenic mechanisms. The synovium and/or cartilage appear to be important in the pathogenesis of beta(2)M amyloidosis (A beta(2)M), as amyloid is not found in the shafts of long bones. The concentration of beta(2)M in the joint fluid parallels that in serum. Once in the joint space, evidence suggests that the beta(2)M binds to collagen in cartilage as the initial site of deposition. This binding may serve as the first step in subsequent amyloid formation, although this remains to be proven. beta(2)M has been shown to have many direct effects on synovial fibroblasts, including induction of the release of cytokines, metalloproteinases, cyclooxygenase-2, and vascular cell adhesion molecule-1 (VCAM-1). The release of these inflammatory mediators that lead to tissue degradation is also observed in other forms of arthritis. Thus beta(2)M itself may elicit the release of inflammatory mediators from synovial fibroblasts even in the absence of cellular infiltrates.

Ca(2+) regulates fluid shear-induced cytoskeletal reorganization and gene expression in osteoblasts.

Osteoblasts subjected to fluid shear increase the expression of the early response gene, c-fos, and the inducible isoform of cyclooxygenase, COX-2, two proteins linked to the anabolic response of bone to mechanical stimulation, in vivo. These increases in gene expression are dependent on shear-induced actin stress fiber formation. Here, we demonstrate that MC3T3-E1 osteoblast-like cells respond to shear with a rapid increase in intracellular Ca(2+) concentration ([Ca(2+)](i)) that we postulate is important to subsequent cellular responses to shear. To test this hypothesis, MC3T3-E1 cells were grown on glass slides coated with fibronectin and subjected to laminar fluid flow (12 dyn/cm(2)). Before application of shear, cells were treated with two Ca(2+) channel inhibitors or various blockers of intracellular Ca(2+) release for 0. 5-1 h. Although gadolinium, a mechanosensitive channel blocker, significantly reduced the [Ca(2+)](i) response, neither gadolinium nor nifedipine, an L-type channel Ca(2+) channel blocker, were able to block shear-induced stress fiber formation and increase in c-fos and COX-2 in MC3T3-E1 cells. However, 1, 2-bis(2-aminophenoxy)ethane-N,N,N',N'-tetraacetic acid-AM, an intracellular Ca(2+) chelator, or thapsigargin, which empties intracellular Ca(2+) stores, completely inhibited stress fiber formation and c-fos/COX-2 production in sheared osteoblasts. Neomycin or U-73122 inhibition of phospholipase C, which mediates D-myo-inositol 1,4,5-trisphosphate (IP(3))-induced intracellular Ca(2+) release, also completely suppressed actin reorganization and c-fos/COX-2 production. Pretreatment of MC3T3-E1 cells with U-73343, the inactive isoform of U-73122, did not inhibit these shear-induced responses. These results suggest that IP(3)-mediated intracellular Ca(2+) release is required for modulating flow-induced responses in MC3T3-E1 cells.

Fluid shear-induced mechanical signaling in MC3T3-E1 osteoblasts requires cytoskeleton-integrin interactions.

Mechanical stimulation of bone induces new bone formation in vivo and increases the metabolic activity and gene expression of osteoblasts in culture. We investigated the role of the actin cytoskeleton and actin-membrane interactions in the transmission of mechanical signals leading to altered gene expression in cultured MC3T3-E1 osteoblasts. Application of fluid shear to osteoblasts caused reorganization of actin filaments into contractile stress fibers and involved recruitment of beta1-integrins and alpha-actinin to focal adhesions. Fluid shear also increased expression of two proteins linked to mechanotransduction in vivo, cyclooxygenase-2 (COX-2) and the early response gene product c-fos. Inhibition of actin stress fiber development by treatment of cells with cytochalasin D, by expression of a dominant negative form of the small GTPase Rho, or by microinjection into cells of a proteolytic fragment of alpha-actinin that inhibits alpha-actinin-mediated anchoring of actin filaments to integrins at the plasma membrane each blocked fluid-shear-induced gene expression in osteoblasts. We conclude that fluid shear-induced mechanical signaling in osteoblasts leads to increased expression of COX-2 and c-Fos through a mechanism that involves reorganization of the actin cytoskeleton. Thus Rho-mediated stress fiber formation and the alpha-actinin-dependent anchorage of stress fibers to integrins in focal adhesions may promote fluid shear-induced metabolic changes in bone cells.

Beam shaping and its solution with the use of an optimization method.

We present an exact mathematical description of beam shaping and indicate that a rigorous solution does not exist: only an optimal solution can be found. An optimization method is proposed to search for the solution. The simulation results for an example are given in detail.

Recursive algorithm for phase retrieval in the fractional fourier transform domain.

We first discuss the discrete fractional Fourier transform and present some essential properties. We then propose a recursive algorithm to implement phase retrieval from two intensities in the fractional Fourier transform domain. This approach can significantly simplify computational manipulations and does not need an initial phase estimate compared with conventional iterative algorithms. Simulation results show that this approach can successfully recover the phase from two intensities.

Balancing the immune system for tolerance: a case for regulatory CD4 cells.

In the past, tolerance mechanisms have focused on processes that involve elimination (deletion) or paralysis (anergy) of immune responses. It is now becoming clearer that peripheral tolerance to antigen depends on the generation of regulatory cells that function to maintain the tolerant state. The development of peripheral tolerance may require that the immune system utilize several strategies, including deletion, anergy, and immunoregulatory pathways, and these strategies may overlap. Recent investigations using animal models of transplantation tolerance have demonstrated that immunoregulatory CD4 mechanisms may play a central role in limiting organ-destructive immune responses. In this Overview, we discuss the rationale behind the need for invoking active regulatory mechanisms in peripheral immunologic tolerance and summarize the data that support or refute a CD4 regulatory mechanism.

Hormonal regulation of insulin-like growth factor binding proteins and insulin-like growth factor I (IGF-I) secretion in porcine stromal-vascular cultures.

We examined the time course of insulin-like growth factor binding protein (IGFBP) secretion and hormonal regulation of IGFBP and IGF-I secretion in porcine stromal vascular (S-V) cultures. Primary cultures of S-V cells derived from porcine adipose tissue were exposed to serum-free media with or without hormone treatment. Time course studies indicated that secretion of four IGFBP (IGFBP-1, -2, -3 and -4) by porcine S-V cells increased with time during the first 3 d after the switch to serum-free conditions and then decreased gradually. Growth hormone treatment stimulated secretion of each IGFBP by 47 +/- 4.7, 46 +/- 10.2, 70 +/- 13.2, and 49 +/- 5.6%, respectively, over control levels. The secretion of IGFBP-1, -2, -3, and -4 was enhanced by 91 +/- 18, 80 +/- 16, 74 +/- 12, and 263 +/- 48%, respectively, in T4-treated S-V cultures compared with untreated cultures. In contrast, dexamethasone reduced the abundance of the IGFBP by 28 to 50% of control levels. Insulin-like growth factor I secretion (844.63 +/- 35.98 pg/mL) in vitro (3 d conditioned media) was increased (P < .05) by GH (1,302.45 +/- 12.95 pg/mL) and T4 (1,291.60 +/- 86.4 pg/mL) and decreased (P < .05) by dexamethasone (552.5 +/- 30.2 pg/mL) (n = 4, S-V cell pools, P < .05). In addition to preadipocytes, other cells in S-V cultures also secrete IGFBP. In conclusion, the secretion of IGF-I and IGFBP by S-V cells is differentially regulated by hormones in vitro.

Influence of thyroxine in vivo on preadipocyte development and insulin-like growth factor-I and IGF binding protein secretion in fetal stromal vascular cell cultures.

Studies were conducted to determine the influence of thyroxine (T4) in vivo on preadipocyte development and insulin-like growth factor-I (IGF-I) and IGF binding proteins (IGFBPs) secretion in stromal-vascular (S-V) cultures. Fetal pigs were hypophysectomized (hypox) at 70 days of gestation, implanted with T4 pellets, and fetuses from the dam at 75 days of gestation. In a second experiment, hypox and T4 implantation were performed at 75 days and fetal pigs removed at 95 days of gestation. Primary cultures of stromal vascular (S-V) cells derived from fetal adipose tissue were established. Cultures were stained for morphological analysis and conditioned media were collected for IGF-1 determination by radioimmunoassay (RIA) and IGFBP analysis by Western blotting. After only 5 days of T4 treatment, fat cell cluster number and size and lipid deposition in cultures were significantly increased compared to cultures from untreated hypox fetuses. Fetal hypox reduced IGF-I secretion by preadipocytes at both ages and T4 treatment completely normalized IGF-I secretion (p < 0.05). Four IGFBPs (BP-1, BP-2, BP-3 & BP-4) detected in S-V cultures derived from 95-day fetuses were decreased in concentration by hypox by 44 +/- 9.4%, 32 +/- 9.7%, 42 +/- 12% and 53 +/- 6.9%. In cultures derived from T4 treated hypox fetuses, the levels of these four IGFBPs were increased by 187 +/- 25%, 239 +/- 38%, 190 +/- 5% and 347 +/- 43% over control values, respectively. In cultures from 75-day fetuses, only IGFBP-2 (major one) and BP-1 (minor one) were detected and their secretion was also decreased by hypox and elevated by T4 treatment (190 +/- 49.5%, 156 +/- 30%, respectively, of controls). The results provide direct evidence that T4 has a major influence on fetal preadipocyte development. T4 stimulated production of IGF-I and IGFBP in fetal S-V cultures, which in turn, may have mediated the capability of T4 to enhance fetal adipose tissue development.