Polylactide pin with transforming growth factor beta 1 in delayed osteotomy fixation

The effect of an absorbable pin containing transforming growth factor beta 1 on fracture healing was studied in a rat model of delayed osteotomy fixation. Transforming growth factor beta 1 was mixed into a blend of L-lactide oligomer and a copolymer of epsilon-caprolactone and DL-lactide that was placed in the grooves of a self reinforced fracture fixation pin made of poly-LD-lactic acid copolymer. A distal femoral osteotomy was made in 54 rats and left untreated. A week later surgery was performed to fix the osteotomy with a fracture fixation pin in 48 rats. In the remaining six rats no fixation was performed. The pin that was used in the study group contained either 5 micrograms (15 rats) or 50 micrograms (15 rats) of the growth factor, while in the control group of 18 rats, an identical pin without growth factor was used. The femurs were examined radiographically, histologically, histomorphometrically, and microradiographically. Tetracycline labeling studies were used after a followup of 1, 3, and 6 weeks. Faster callus formation in the transforming growth factor beta 1 treated animals but no acceleration in the healing of the osteotomy is reported. The addition of bone growth factors to bioabsorbable fracture fixation materials may enhance bone healing.     

Expression of transforming growth factor beta and transforming growth factor beta receptors on AIDS-associated Kaposi's sarcoma

Several humoral growth factors may contribute to the development and growth of AIDS-associated Kaposi's sarcoma (KS). They are either provided by chronically activated cells of the immune system or in an autocrine/paracrine manner by the neoplastic cells themselves. Transforming growth factor beta(TGF-beta) may directly enhance the growth of KS cells and tumor matrix formation. To mediate a signal both TGF-beta receptors type I and type II (TbetaR-I and TbetaR-II) have to be expressed. We investigated the expression of TGF-beta, TGF-beta receptors types I and II, and endoglin, a nonsignaling-type TbetaR-III, by means of immunohistochemistry on skin biopsies from patients with AIDS-related KS. We found that the TGF-beta ligand was expressed by KS cells in 9 of 11 samples. TbetaR-II was strongly expressed in 10 of 12 samples, but none of the investigated tumor samples stained for TbetaR-I. Endoglin was weakly expressed on all KS lesions and stained the endothelium of tumor-associated vessels in 92% of the samples. These findings show that most KS lesions have the ability to produce TGF-beta and that KS cells maintain a high expression of TbetaR-II in the absence of TbetaR-I, which may allow KS to escape growth inhibitory effects of endocrine or paracrine TGF-beta.     

Increased urinary endothelin excretion in patients with liver cirrhosis

Six girls (five Saudis and one Sudanese) aged between 3.5 and 12 years demonstrated the classic features of Rett syndrome (RS), including developmental regression with dementia, loss of acquired speech and hand function, and stereotypic hand movements. Myoclonic seizures were observed in two of them. Electroencephalography showed diffuse slowing in three cases generalized epileptic discharges in one, and normal findings in two. Cranial computed tomography revealed normal findings, except in the 12-year-old girl who had mild bilateral frontal lobe atrophy. Except for mildly elevated blood ammonia in three patients, associated with slightly elevated blood lactate in two of them, results of neurometabolic screening tests were normal. There are, as yet, no laboratory markers pathognomonic for RS. Hence, adherence to current diagnostic criteria is essential. To prevent unnecessary and costly investigations, especially in developing countries, wider knowledge of the clinical features of the syndrome is warranted.     

Purification of transforming growth factor beta 1 from human platelets

Transforming growth factor-beta (TGF beta) is a growth and differentiation factor which can be released from many cell types. In previous studies, platelets were identified as a rich source of TGF beta. Here we present a rapid and convenient method for TGF beta purification from human platelets which includes acid-ethanol extraction and gelfiltration, cation exchange and reversed phase chromatography. All purification steps are performed under acidic conditions to prevent adsorption of TGF beta to the vial walls. In addition, volatile solvents and buffers were used which allowed easy removal of solvent and salt by lyophilization. Using this method pure TGF beta can be easily obtained in high yield (370 micrograms) from 20 units of platelet concentrate.     

High levels of transforming growth factor beta 1 in patients with colorectal cancer: association with disease progression

BACKGROUND & AIMS: Contribution of transforming growth factor beta 1 (TGF-beta 1) to tumor progression has been suggested. However, little is known about the role of TGF-beta 1 in colorectal cancer. Plasma TGF-beta 1 levels and its expression were analyzed in patients with colorectal cancer. METHODS: Plasma TGF-beta 1 levels were measured in 22 patients with colorectal cancer using a TGF-beta 1 enzyme-linked immunosorbent assay. Expression of TGF-beta 1 messenger RNA and immunohistochemical distribution of the protein in colorectal cancer tissues were examined. RESULTS: Plasma TGF-beta 1 levels in patients with colorectal cancer (14.8 +/- 8.4 ng/mL) were significantly higher than in normal controls (1.9 +/- 1.4; n = 22) (P < 0.001). After curative surgical resection, plasma TGF-beta 1 levels decreased in examined patients from 11.9 +/- 6.7 to 3.8 +/- 1.2 ng/mL (P < 0.01). TGF-beta 1 messenger RNA was about 2 1/2 times more abundant in colorectal cancer tissues than in control (P < 0.01). TGF-beta 1 was detected in the cytoplasm of colorectal cancer cells immunohistochemically. Both TGF-beta 1 messenger RNA expression in colorectal adenocarcinoma tissues and its plasma levels were associated with tumor stage of Dukes' classification (P < 0.05). CONCLUSIONS: These results suggest that plasma TGF-beta 1 levels may reflect overexpression of the gene in colon cancer tissues and are associated with disease progression.     

Increased 24-hour endothelin-1 urinary excretion in patients with chronic obstructive pulmonary disease

Abnormalities in endothelin-1 (ET-1) pulmonary metabolism have been reported in patients with pulmonary hypertension, asthma and chronic obstructive pulmonary disease (COPD). In this study we have evaluated the 24-hour urinary excretion of ET-1 in COPD patients both during acute exacerbation and stable phase of the disease. ET-1 plasma and urinary levels were measured in 13 COPD patients on admission to the hospital for an acute exacerbation and at the recovery period. Ten healthy volunteers were also studied. Determination of plasma and 24-Hour urinary ET-1 levels were carried out with a radioimmunoassay test. Plasma ET-1 levels in COPD patients were similar during exacerbation and recovery and were not significantly different from those in the healthy subjects. 24-hour urinary excretion of ET-1 was increased in COPD patients during acute exacerbation; it decreased during recovery, but remained elevated when compared to normal subjects. A negative correlation was found between arterial oxygen pressure and ET-1 excretion; no correlation was found between plasma and urinary ET-1 values. In conclusion, COPD patients excrete higher amounts of ET-1 compared to healthy subjects. Urinary ET-1 values are further increased during acute exacerbation of the disease.     

The effect of epidermal growth factor and transforming growth factor beta 1 on proliferation and differentiation of urothelial cells in urinary bladder explant culture

The presence of the virulence markers K1 capsule, serum resistance, aerobactin, S and P/PR fimbriae were examined in a total of 395 E. coli strains from different extraintestinal infections and in 81 faecal isolates of healthy volunteers using specific DNA probes and classical phenotypic methods. All markers were more frequently detected when genotypic assays were applied. The simultaneous occurrence of 3-4 virulence determinants was typical for isolates derived from patients with septicaemia or meningitis. Isolates from blood cultures and cerebrospinal fluid were expressing the virulence phenotypes to a greater extent than isolates from urine or faeces. The use of colony hybridization with specific oligonucleotide and polynucleotide probes for the detection of virulence determinants has been proven to be more specific and reliable than phenotypic approaches.     

Down-regulated expression of transforming growth factor beta 1 mRNA in endometrial carcinoma

Transforming growth factor beta1 (TGF-beta1) is a potent modulator of cell proliferation in vitro, and recent studies have demonstrated its overexpression in several different tumours; nevertheless, the molecular mechanisms of TGF-beta1 action on cell growth and differentiation have not been fully elucidated. To clarify the role of TGF-beta and its receptor in human endometrial proliferation and differentiation, TGF-beta1 expression at both the mRNA and protein levels has been evaluated by using Northern blotting and immunohistochemistry, in both normal (atrophic, proliferative and secretory) and neoplastic (adenocarcinoma) endometrial samples. This study demonstrates that TGF-beta1 mRNA expression is dramatically reduced in endometrial carcinomas with respect to non-neoplastic tissues, whereas the immunohistochemical expression of TGF-beta1 is enhanced in the epithelial component of endometrial carcinomas compared with non-neoplastic tissues. These data suggest that TGF-beta1 acts as a paracrine regulator of endometrial cell proliferation and that it may contribute to the carcinogenic mechanisms of endometrial carcinoma.     

Plasma levels of transforming growth factor beta 1 in chronic liver disease

We describe the case of a 30-year-old female patient with a 7-year history of multiple sclerosis, who presented with an 18-month history of secondary amenorrhoea and vague symptoms which included poor sleep and impaired concentration. Endocrine investigations revealed hypogonadotrophic hypogonadism and GH deficiency, a probable consequence of a hypothalamic plaque. This is the first report of hypogonadotrophic hypogonadism and GH deficiency occurring in conjunction with multiple sclerosis. As such, it should raise suspicion of endocrine dysfunction occurring in a condition with such a vast spectrum of disability as multiple sclerosis.     

Relationship of transforming growth factor beta 1 to angiogenesis in gastric carcinoma

OBJECTIVE: To evaluate the prevalence of risk factors of coronary heart disease in the personnel of the General Hospital in Mexico City. MATERIAL AND METHODS: We studied 2,228 workers, 1,531 female (68.7%) and 697 male (31.2%) whose ages ranged from 16 to 65 years old in the period of 1993 to 1995. They were divided in work areas: Intendancy 477 (21.4%), Administrative, 697 (31.2%), Physicians, 495 (22.2%) and Nurses, 559 (25.0%). We collected clinical histories, anthropometric measures, and laboratory determinations of glucose, total cholesterol, LDL, HDL and triglicerydes. RESULTS: We found that 367 (14.9%) had total cholesterol above 240 mg/dl, with high values in females of the administrative area (17.1%) and males in the nursing department (26%), which was the highest tendency. Trigliceryde levels above 200 mg/dl were found in 208 males (24.6%) and 263 females (16.2%), with high prevalence in the nursing and administrative departments, in males (39.1 and 34.1% respectively). Obesity was present in 236 females (14.5%) and 97 males (11.5%). High blood pressure in 549 individuals (22.2%), 297 females (18.3%) and 252 males (29.8%) without significance regarding to work area. Smoking habits were positive in 32% of the total with highest prevalence in males from 30 to 45 years and in females from 30 to 50 years. We found an incidence of 6.24% of diabetes in all the subjects studied, 2.27% ignored the diagnosis at the moment they were studied. CONCLUSIONS: In this study we confirmed the high prevalence of risk factors of coronary heart disease in personnel of the General Hospital in Mexico City. In most cases, these risk factors that can be modified and, therefore, prevented.     

Effect of 13-cis-retinoic acid and alpha-interferon on transforming growth factor beta1 in patients with rising prostate-specific antigen

The objective of this study was to test the hypothesis that 13-cis-retinoic acid (CRA) and alpha-interferon (IFN-alpha) have antitumor activity in patients with early recurrence of prostate cancer measured by rising prostate-specific antigen (PSA) after local therapy, and that this activity is associated with the increase of plasma transforming growth factor beta1 (TGF-beta1). Thirty patients with a PSA > 7 ng/ml that increased >0.4 ng/ml/month after initial radiation therapy or a PSA > 2.0 ng/ml after prostatectomy were treated with 1 mg/kg/day of CRA and 3 million units of IFN-alpha administered three times per week. Patients were followed clinically with serum measurements of PSA and assessment of toxicity. Biological activity of CRA and IFN-alpha was assessed by the measurement of plasma TGF-beta1. Twenty-six percent of patients had a partial (50% decrease maintained for 1 month) or minimal (<50% decrease maintained for 1 month) biochemical response of PSA, with a median decrease of 23% (11-55%) at 3 months. Plasma TGF-beta1 levels increased with CRA and IFN-alpha therapy and correlated with a decrease in PSA; patients with a decrease in PSA had a 151% increase in TGF-beta1 compared to 27% in patients without a decrease in PSA (P = 0.04). CRA and IFN-alpha can produce transient reduction or stabilization of PSA. The measurement of plasma TGF-beta1 at 1 month of therapy correlates with changes in PSA and may represent a useful marker for the biological effect of these agents; further analysis in larger numbers of patients and methods to optimize these effects should be explored.     

Phase 1 trial of transforming growth factor beta 2 in chronic progressive MS

Transforming growth factor (TGF)-beta2 is a pleiotropic cytokine associated with remissions in multiple sclerosis (MS) and amelioration of allergic encephalomyelitis. We assessed the safety of TGF-beta2 in an open-label trial of 11 patients with secondary progressive (SP) MS. Five patients had a reversible decline in the glomerular filtration rate. There was no change in expanded disability status scale or MRI lesions during treatment. Systemic TGF-beta2 may be associated with reversible nephrotoxicity, and further investigation of its therapeutic potential in MS should be performed with caution.     

Plasma transforming growth factor beta1 as a predictor of radiation pneumonitis

PURPOSE: To investigate prospectively the utility of plasma transforming growth factor beta1 (TGFbeta1) as a marker for the development of symptomatic radiation pneumonitis. MATERIALS AND METHODS: Seventy-three patients with lung cancer treated with curative intent are reported herein. Plasma TGFbeta1 samples were obtained before, weekly during, and at each follow-up after radiation therapy (RT). TGFbeta1 was extracted using an acid/ethanol method. An enzyme-linked immunosorbent assay was used to quantify plasma TGFbeta1 concentrations. The TGFbeta1 level at the end of RT was considered "normal" if it was both < or = 7.5 ng/ml and less than the pretreatment value. All patients were followed for at least 6 months, unless symptomatic pneumonitis developed sooner. Pneumonitis was defined by National Cancer Institute (NCI) common toxicity criteria. RESULTS: Fifteen of the 73 patients (21%) developed symptomatic pneumonitis and the remaining 58 (79%) did not. A normal plasma TGFbeta1 by the end of RT, as defined above, was more common in patients who did not develop pneumonitis. A return of the plasma TGFbeta1 to normal accurately identified patients who would not develop pneumonitis with both a sensitivity and positive predictive value of 90%. CONCLUSION: Plasma TGFbeta1 levels appear to be a useful means to identify patients at low risk for the development of pneumonitis from thoracic RT. Thus, monitoring of plasma TGFbeta1 levels may identify candidates for dose escalation studies in the treatment of lung cancer.     

Role of transforming growth factor beta 1 (TGF beta 1) in mediating androgen-induced growth inhibition in human adrenal cortex in vitro

We have previously found that the androgen receptor gene is expressed both in normal and adenomatous human adrenal cortex and in the NCI-H295 human adrenocortical cancer cell line. Furthermore, we have observed that dihydrotestosterone (DHT) at physiological concentrations (10(-11) M) inhibits human adrenocortical cell growth in vitro and slightly decreases c-myc RNA levels in NCI-H295 cells. As c-myc is probably not the main mechanism mediating DHT-induced inhibition of cell growth, other genes controlling cell proliferation may be involved. Transforming Growth Factor beta (TGF beta) is a regulatory peptide that acts by both autocrine and paracrine mechanisms to control proliferation and differentiation, and there is previous evidence that TGF beta may exert an antimitotic effect on human fetal adrenal cells in vitro. This study examines a possible role for TGF beta 1 in mediating the DHT-induced reduction of human adrenocortical cell growth. TGF beta 1 and its receptor (TGF beta RII) are expressed in DHT-treated and nontreated NCI-H295 cells; on Northern blot analysis 24-h treatment with DHT (10(-11) M) produced a small increase in TGF beta RII RNA, and quantitative RT-PCR showed a 1.5-fold increase in TGF beta 1 RNA levels. These findings suggest that TGF beta 1 and its receptor may be involved in DHT-induced inhibition of human adrenocortical cell growth.     

Influenza virus neuraminidase activates latent transforming growth factor beta

Transforming growth factor beta (TGF-beta) is a family of proteins secreted by virtually all cells in a biologically inactive form. TGF-beta levels increase during many pathophysiological situations, including viral infection. The mechanism for increased TGF-beta activity during viral infection is not understood. We observed an increase in active TGF-beta levels within 1 day in mice infected with influenza virus. Further studies showed that the neuraminidase glycoprotein of influenza A and B viruses directly activates latent TGF-beta in vitro. There are sufficient levels of TGF-beta activated by virus to induce apoptosis in cells. In addition, influenza virus-induced apoptosis is partially inhibited by TGF-beta-specific antibodies. These novel findings suggest a potential role for activation of TGF-beta during the host response to influenza virus infection, specifically apoptosis. This is the first report showing direct activation of latent TGF-beta by a viral protein.     

Increased incidence of apoptosis in transforming growth factor alpha-deficient mouse blastocysts

Platelets, activated by various agonists, produce microparticles (MP) from the plasma membrane, which are released into the extracellular space. Although the mechanism of MP formation has been clarified, their biological importance remains ill defined. We have recently shown that platelet-derived MP influence platelet and endothelial cell function. In this study, we have further examined the mechanism of cellular activation by platelet MP. To address the possibility that they may influence monocyte-endothelial interactions, we used an in vitro assay to examine their effects on the adhesion of monocytes to human umbilical vein endothelial cells (HUVEC). Platelet MP increased the adhesion of monocytes to HUVEC in a time- and dose-dependent manner. Maximal adhesion of monocytes to resting HUVEC was observed after 24 h of stimulation with MP. Similar kinetics were observed with U-937 (human promonocytic leukemia) cells, used as a model for the blood-borne monocyte. Maximal adhesion of resting monocytes to MP-stimulated HUVEC was observed after 5 h of stimulation with MP. The EC50s for MP-induced increases in HUVEC, monocyte, and U-937 cell adhesion is 8.74, 43.41, and 10.83 microg/ml of MP protein, respectively. The induction of monocyte-endothelial adhesion was mimicked by arachidonic acid isolated from MP. The observed increased cellular adhesiveness correlated with MP-induced upregulation of cell adhesion molecules. MP-stimulated HUVEC increased intracellular cell adhesion molecule-1 (ICAM-1) but not vascular cell adhesion molecule-1 (VCAM-1), P-, or E-selectin expression. Monocyte and U-937 lymphocyte function-associated antigen-1 (CD11a/CD18) and macrophage antigen-1 (CD11b/ CD18, alpham/beta2) were both upregulated upon MP stimulation, but an increase in p150,95 (CD11c/CD18), very late antigen-1, or ICAM-1 expression was not observed. The functional importance of these changes was demonstrated with blocking antibodies. MP also induced the chemotaxis of U-937 cells in a dose-dependent manner with an EC50 of 4.40 microg/ml of MP protein. Similarly, arachidonic acid isolated from MP mimicked the chemotactic response. A role for PKC was implicated in both adhesion and chemotaxis. GF 109203X, a specific inhibitor of PKC, significantly reduced monocyte-endothelial adhesion, as well as U-937 chemotaxis. The demonstration that platelet MP may modulate important aspects of endothelial and monocyte function provides a novel mechanism by which platelets may interact with such cells in human atherosclerosis and inflammation.     

Function of the type V transforming growth factor beta receptor in transforming growth factor beta-induced growth inhibition of mink lung epithelial cells

The type V transforming growth factor beta (TGF-beta) is a 400-kDa nonproteoglycan membrane protein that co-expresses with the type I, type II, and type III TGF-beta receptors in most cell types. The type V TGF-beta receptor exhibits a Ser/Thr-specific protein kinase activity with distinct substrate specificity (Liu, Q., Huang, S. S., and Huang, J. (1994) J. Biol. Chem. 269, 9221-9226). In mink lung epithelial cells, the type V TGF-beta receptor was found to form heterocomplexes with the type I TGF-beta receptor by immunoprecipitation with antiserum to the type V TGF-beta receptor after 125I-TGF-beta affinity labeling or Trans35S-label metabolic labeling of the cells. The kinase activity of the type V TGF-beta receptor was stimulated after treatment of mink lung epithelial cells with TGF-beta. TGF-beta stimulation resulted in the growth inhibition of wild-type mink lung epithelial cells and to a lesser extent of the type I and type II TGF-beta receptor-defective mutants, although higher concentrations of TGF-beta were required for the growth inhibition of these mutants. TGF-beta was unable to induce growth inhibition in human colorectal carcinoma cells lacking the type V TGF-beta receptor but expressing the type I and type II TGF-beta receptors. These results suggest that the type V TGF-beta receptor can mediate the TGF-beta-induced growth inhibitory response in the absence of the type I or type II TGF-beta receptor. These results also support the hypothesis that loss of the type V TGF-beta receptor may contribute to the malignancy of certain carcinoma cells.     

Increased urinary adrenomedullin excretion in children with urinary-tract infection

BACKGROUND: Adrenomedullin (AM), a smooth-muscle relaxant peptide, is stimulated by cytokines and bacterial endotoxins. We hypothesized that urinary-tract infections may be associated with elevated urinary AM excretion. METHODS: AM in urine was quantified in eleven children with urinary-tract infection and 11 age- and sex-matched controls by radioimmunoassay. RT-PCR was used to demonstrate local AM mRNA expression in the urinary tract. RESULTS: In healthy controls but not in diseased children there was a significant correlation between AM and creatinine in urine (r = 0.91, P < 0.001). AM levels in children with urinary-tract infection were significantly higher than in controls (0.6 +/- 0.41 vs 0.15 +/- 0.14 ng/micromol creatinine; P < 0.001; (means +/- SD)). There was a significant correlation between white cell count and AM in urine (r = 0.78, P < 0.001). AM mRNA was expressed in renal tissue, renal pelvis, ureter, bladder, and urethra. CONCLUSION: The smooth-muscle relaxant peptide adrenomedullin that is synthesized in tissue of the human urinary tract is elevated in urine of patients with urinary-tract infections. A possible consequence might be the interference with the ureteral anti-reflux mechanisms.