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Biomedical subjects

M Bodo

Publications and source records attributed to M Bodo.

At least 19 recordsLinked to original sources

REG can be used to detect cerebrovascular alteration caused by alcoholism.

Despite recent evidence of the beneficial effects of moderate alcohol consumption in arteriosclerosis prevention, the neurotoxic effects of alcohol abuse are well known. Our hypothesis was that uncontrolled alcohol consumption may cause cerebrovascular damage detectable by rheoencepholography (REG), a noninvasive bio-impedance technique for estimating cerebral blood flow. Test subjects were 48 alcoholic patients in Hungary; the control group consisted of 12 drug-addicted and depressed patients in Hungary and 13 healthy male subjects in the United States. Additional subgroups were formed according to smoking habits and average daily alcohol dose. REG was measured by a computer-based system, "Cerberus"; REG anacrotic time above 180 ms was considered pathological. ANOVA showed that daily alcohol consumption and smoking were significantly higher in alcoholics than in drug-addicted and depressed patients. Twelve alcoholics showed a pathological REG anacrotic time. Longer REG anacrotic time was correlated with higher daily alcohol consumption. In the alcoholic group, the steeper regression line of REG slope reflected the pathological impact of alcohol abuse. The healthy control sample showed a nearly identical slope for both REG and age. The correlation of increased REG anacrotic time and daily alcohol consumption supports the hypothesis that REG detects accelerated cerebrovascular aging (arteriosclerosis) in alcoholic subjects.

Adult↗

Changes in the intracranial rheoencephalogram at lower limit of cerebral blood flow autoregulation.

Cerebral blood flow (CBF) reactivity monitoring is an appropriate primary parameter to evaluate cerebral resuscitation due to a systemic or regional cerebral injury leading to possible irreversible brain injury. Use of the electrical impedance method to estimate CBF is rare, as the method's anatomical background is not well understood. Use of intracranial rheoencephalography (iREG) during hemorrhage and comparison of iREG to other CBF measurements have not been previously reported. Our hypothesis was that iREG would reflect early cerebrovascular alteration (CBF autoregulation). Studies comparing iREG, laser Doppler flowmetry and ultrasound were undertaken on anesthetized rats to define CBF changes during hemorrhage. Blood was removed at a rate required to achieve a mean arterial blood pressure (MABP) of 40 mm Hg over 15 min. Estimation of CBF was taken with intracranial, bipolar REG (REG I; n=14), laser Doppler flowmetry (LDF; n=3) and carotid flow by ultrasound (n=11). Data were processed off-line. During the initial phase of hemorrhage, when MABP was close to 40 mm Hg, intracranial REG amplitude transiently increased (80.94%); LDF (77.92%) and carotid flow (52.04%) decreased and changed with systemic arterial pressure. Intracranial REG amplitude change suggests classical CBF autoregulation, demonstrating its close relationship to arteriolar changes. The studies indicate that iREG might reflect cerebrovascular responses more accurately than changes in local CBF measured by LDF and carotid flow. REG may indicate promise as a continuous, non-invasive life-sign monitoring tool with potential advantages over ultrasound, the CBF measurement technique normally applied in clinical practice. REG has particular advantages in non-hospital settings such as military and emergency medicine.

Animals↗

Cerebrovascular reactivity: rat studies in rheoencephalography.

Here we describe a correlative study of cerebral blood flow (CBF) using global, local CBF and carotid flow measurements. The primary objective of this study was to establish a relationship between REG and CBF autoregulation. Rheoencephalography (REG), a rarely used method to measure CBF, is a potential tool of non-invasive continuous life sign monitoring and detection of early cerebrovascular alteration. However, the anatomical background of REG is not clearly understood. Two experimental studies were undertaken on anesthetized rats to define two CBF measurements: (1) CO2 inhalation, and, (2) clamping of common carotid arteries. Measurement of CBF was taken with REG, laser Doppler flowmetry (LDF) and carotid flow by Doppler ultrasound. Data were off-line processed. During CO2 inhalation, the increases in REG and LDF were significant (p = 0.0001), while carotid flow and systemic arterial pressure decreased. During carotid artery clamping, the decrease in REG and Doppler ultrasound was significant (p = 0.0001). REG showed cerebrovascular reactivity, indicating the relationship to arteriolar changes. Compared to LDF and carotid flow, only REG showed the classical CBF autoregulation.

Animals↗

Immunogenicity of recombinant type IX collagen in murine collagen-induced arthritis.

OBJECTIVE: Past attempts to isolate type IX collagen (CIX) from cartilage using limited proteolysis yielded partially degraded material. Recent application of recombinant technology, however, has allowed the preparation of intact native CIX. We used the murine collagen-induced arthritis model to characterize the immunologic properties of recombinant human CIX (rCIX) produced using a baculovirus expression system. METHODS: A panel of B10 congenic mice was immunized with rCIX emulsified with Freund's complete adjuvant (CFA). The ability of the rCIX to induce tolerance and suppress arthritis was determined by administration intravenously or orally before challenge with CII/CFA. RESULTS: None of the mice immunized with rCIX developed overt arthritis, although 2 of 5 HLA-DR1 transgenic mice developed limited digital erythema and swelling. Recombinant CIX administered by either route effectively induced suppression of arthritis, although the suppression was less pronounced than that induced with CII. Immune responses to CIX and CII were specific, suggesting that bystander suppression, rather than cross-reactivity with CII, was instrumental in suppressing arthritis. CONCLUSION: These data show that CIX down-regulates arthritis in mice while having no associated risk of inducing arthritis.

Administration, Oral↗

DNA cytometry confirms the utility of the Bethesda system for the classification of Papanicolaou smears.

BACKGROUND: Developed in 1989, the Bethesda System has largely replaced previous classifications of Papanicolaou (Pap) smears from the uterine cervix. The system is binary, dividing smears into two groups - low-grade, squamous, epithelial lesions (LSIL) or high-grade, squamous, epithelial lesions (HSIL). A third category, atypical squamous cells of undetermined significance (ASCUS), is used to classify minimal cellular changes that do not satisfy the criteria for the low- or high-grade categories. This study was designed to confirm the utility of this binary division and to compare the results with another classification system (the Munich II Nomenclature) that is not binary but contains three divisions or grades for dysplasia - low, intermediate, and high. METHODS: Pap smears were obtained from 593 women with a cytologic diagnosis of dysplasia based on the Munich System. Smears were then classified by the Bethesda System into LSIL or HSIL. Patients were followed for 2 years either with biopsy or repeat cytology. The initial smears were restained by the Feulgen method, and ploidy was evaluated by interactive DNA cytometry. RESULTS: Of 241 cases of LSIL, 39% were diploid, 57% polyploid, and 4% aneuploid. Of 352 cases classified HSIL, 4% were diploid, 17% polyploid, and 79% aneuploid. After 2 years of follow-up, 2 of 108 patients who were biopsied and who were originally classified as diploid progressed to cervical intraepithelial neoplasia/carcinoma in situ (CIN/CIS) whereas 109 of 217 patients who were aneuploid and biopsied were found to have CINIII/CIS. CONCLUSIONS: The two divisions of the Bethesda System, LSIL and HSIL, correlated with ploidy as evaluated by cytometry. Aneuploidy was found to be useful to separate cases of HSIL from those of LSIL as defined in the Bethesda System. Because of the binary division, use of a system with three divisions for dysplasia, such as the Munich II Nomenclature, creates a therapeutic dilemma because a single diagnostic category (usually the intermediate grade) may contain both self-limiting and progressive lesions. DNA cytometry of Pap smears was found to be useful as a routine procedure.

Carcinoma in Situ↗

Screening for cerebroprotective agents using an in vivo model of cerebral reversible depolarization in awake rats.

The need to screen cerebroprotective compounds without anesthetic interference prompted the development of a model using hypoxic rats. In this model two outcome measures were used: (1) the time to reach isoelectric electroencephalogram (iEEG), caused by nitrogen gas inhalation in the test chamber, and (2) the time for behavioral recovery measuring the latency of restoration of the head-withdrawal reflex upon vibrissae stimulation. We report here data of blood chemistry, cerebral tissue oxygen measurements, a definition of a proposed scoring system, and the pharmacological results of RGH-2202. The findings with RGH-2202 are used here to show the utility of the screening method. Events during hypoxia: Arterial and venous pO(2), pCO(2), and pH, and brain tissue pO(2)significantly declined. Significant correlations were established among the pO(2)of cerebral tissue, blood, and the test chamber. RGH-2202 significantly and dose-dependently shortened the iEEG time; the compound's Effective Dose(30)was 227.8 mg kg(-1). Events during recovery: Immediately after the iEEG, when the atmosphere in the chamber was replaced with room air, the arterial, venous and brain tissue pO(2)increased above the control level and subsequently recovered to baseline levels. Behavioral recovery occurred before blood chemistry was otherwise normalized. RGH-2202 significantly and dose-dependently shortened the recovery time; the Effective Dose(30)was 8.71 mg kg(-1). The available data define and support the physiological basis of this practicable rat-screening model.

Administration, Oral↗

Silica and its antagonistic effects on transforming growth factor-beta in lung fibroblast extracellular matrix production.

BACKGROUND: Silicosis, a pneumoconiosis marked by interstitial pulmonary fibrosis, is caused by inhalation of free crystalline silica particles. When silica particles are injected into the lower lung, they are translocated across the epithelium into the interstitial space, where macrophage-derived growth factors affect lung fibroblast proliferation and collagen deposition. We hypothesized that silica may act directly on pulmonary fibroblasts modifying extracellular matrix (ECM) synthesis and that the effects of silica may be mediated by transforming growth factor-beta (TGFbeta) overproduction. METHODS: To test this hypothesis, we studied a human lung fibroblast cell line (WI-1003) exposed to silica in vitro. We investigated cell morphology by electron microscopic procedure, cell growth, collagen production, and glycosaminoglycans (GAG) composition by radiolabeled precursors. Cytokine and growth factor synthesis were evaluated by specific enzyme-linked immunoadsorbent assay kits and Northern blotting analysis. RESULTS: Pulmonary fibroblasts internalized silica particles without detectable cell damage. Silica directly stimulated collagen synthesis and decreased the amount of 3H-glucosamine-labeled GAG. Silica-treated fibroblasts secreted less TGFbeta than untreated controls, antagonized the stimulatory effect of TGFbeta on ECM synthesis, and reversed TGFbeta-induced inhibition of cell proliferation. Northern blotting analysis showed increased interleukin-1alpha (IL-1alpha) mRNA after silica treatment. IL-1alpha had no influence on collagen synthesis but increased the number of WI-1003 fibroblasts. CONCLUSIONS: These results support our hypothesis that lung fibroblasts are direct silica targets. However, contradicting our hypothesis, silica antagonized TGFbeta activities through a TGFbeta downregulation and an IL-1alpha upregulation. The complex pattern of TGFbeta and IL-1alpha regulation in pulmonary fibroblasts is imbalanced by silica exposure and might play a key role in silica-mediated pulmonary fibrosis.

Cell Division↗

Bronchial epithelial cell matrix production in response to silica and basic fibroblast growth factor.

BACKGROUND: Previous studies show that macrophages, lung fibroblasts, and their soluble mediators are responsible for the onset and development of pulmonary fibrosis. This study was conducted to determine whether airway epithelial cells are also directly involved in response to fibrogenic agents and consequently in the pathogenesis of lung fibrosis. To verify the hypothesis, we determined whether silica acts directly on human bronchial epithelial cells by stimulating cytokine and growth factor release and by modifying matrix production. MATERIALS AND METHODS: An SV40 large T antigen-transformed human airway epithelial cell line, 16HBE14o (16HBE), was used. The expression profile of some proinflammatory interleukins (ILs), such as IL-1alpha, IL-1beta and IL-6 and their modulation by silica, were evaluated by polymerase chain reaction (PCR) analysis. Transforming growth factor beta (TGFbeta) and basic fibroblast growth factor (bFGF) mRNA levels were tested by Northern blotting in the presence and in the absence of silica. The silica- and/or bFGF-induced effects on matrix components (total proteins, collagen, and fibronectin) were also evaluated using radio-labeled precursors. RESULTS: The results demonstrated 16HBE internalized silica particles. Silica induced a little IL-6 secretion, without affecting IL-1 and TGFbeta isoform production and strongly stimulated bFGF mRNA level and bFGF protein secretion. Silica also induced changes in 16HBE production of total proteins, collagen, and fibronectin production. When added in combination with the growth factor, it strengthened bFGF stimulation of matrix component secretion. CONCLUSIONS: These results support the hypothesis that the changes in matrix components are due to a direct effect of silica on bronchial epithelial cells. Silica-induced over-secretion of bFGF suggests that autocrine and paracrine differentiation loops for bFGF may also be operative and that these mechanisms may be involved in the pathogenesis of pulmonary fibrosis. In the future, cytokine-directed therapeutic strategies might find a place in clinical practice.

Blotting, Northern↗

Epithelial-mesenchymal interactions and lung branching morphogenesis. Role of polyamines and transforming growth factor beta1.

Lung branching morphogenesis is a result of epithelial-mesenchymal interactions, which are in turn dependent on extracellular matrix composition and cytokine regulation. Polyamines have recently been demonstrated as able to modify chick embryo skin differentiation. In this work we have examined the effects of putrescine and spermidine during chick embryo lung morphogenesis in organotypic cultures by morphological, histochemical and biochemical examination. To verify the role of polyamines, we used specific inhibitors, such as bis-cyclohexylammonium sulphate and alfa-difluoromethylornithine, and transforming growth factor beta1, an ornithine decarboxylase and polyamine stimulator. Our data show that lung morphogenesis is significantly altered following the induced mesenchymal glycosaminoglycan changes. The increase of mesenchymal glycosaminoglycans is correlated with a stimulation of lung development in the presence of polyamines, and with its inhibition when transforming growth factor beta1 is added to the culture medium. The morphometric data show a uniform increase of both the mesenchyme and epithelial branching with spermidine and putrescine stimulus, whereas the mesenchymal substance alone is significantly increased in apical-median lung sections with transforming growth factor beta1 and transforming growth factor beta1 + spermidine lung cultures. Transforming growth factor beta1 and transforming growth factor beta1 + spermidine confirm the blocking of epithelial branching formations and fibroblast activation, and show that polyamines are unable to prevent the blocking of epithelial cells due to the inhibitory effect of transforming growth factor beta1.

Animals↗

Interleukin secretion, proteoglycan and procollagen alpha(1)(I) gene expression in Crouzon fibroblasts treated with basic fibroblast growth factor.

The present study provides the first evidence that fibroblasts obtained from patients affected by Crouzon syndrome, a rare craniosynostosis, despite mutations in the high-affinity bFGF receptor retain their capacity to respond to bFGF. The growth factor reduces IL-1 secretion, downregulates biglycan and procollagen alpha(1)(I), and increases betaglycan expression. Since betaglycan is a co-receptor for bFGF signalling, an alternative signal transduction pathway is suggested in Crouzon fibroblasts, to explain the documented changes in ECM macromolecule production.

Adolescent↗

Cerebroprotective drugs shorten the hypoxia-induced onset of electrical silence in unanesthetized rats.

Pharmacological agents that delay the hypoxic arrest of neuronal electrical activity, as indicated by the suppression of electroencephalogram (EEG), have previously been thought to increase brain resistance to oxygen insufficiency. On the other hand, acceleration of the EEG suppression may offer some protection against severe hypoxia by reducing neuronal energy spending on electrogenesis. In unanesthetized rats we examined the effects of several antihypoxic drugs on the time of appearance of isoelectric EEG (tiEEG), caused by normobaric hypoxia. In addition, alterations in cerebral blood flow induced by hypoxia and by some drugs were monitored using polarographic techniques to determine if cerebrocirculatory changes play a significant role in the drug effects on tiEEG. We also assessed drug effects on behavioral recovery after hypoxia by measuring the latency of restoration of the head-withdrawal reflex upon vibrissae stimulation. Pentobarbital (30 and 60 mgkg(-1)i.p.), chloralhydrate (400 mgkg(-1)i.p.) flunarizine (50-100 mgkg(-1)p.o.), hydergine (3-50 mgkg(-1)p.o.), nicergoline (50 mgkg(-1)and 85 mgkg(-1)p.o.), sabeluzole (3 and 7.5 mgkg(-1)i.p.) and vincamine (80 mgkg(-1)p.o.) reduced tiEEG (mean 27.1 +/- 3.3 min prior to drugs). In contrast, idebenone (29-85 mgkg(-1)p.o.) and vinpocetine (29-85 mgkg(-1)p.o.) had no significant effects on tiEEG. The divergent effects on cerebral blood flow suggest an insignificant role for cerebrocirculatory changes in the drug-induced reduction of tiEEG during severe hypoxia. The drug effects on recovery of the head-withdrawal reflex (mean 4.2 +/- 1.3 min prior to drugs) varied from a delay (sabeluzole) to acceleration (flunarizine) with no correlation to the effects on tiEEG, suggesting that EEG criteria alone may not predict the course of functional recovery.

Anesthesia↗

Liposome-induced pulmonary hypertension: properties and mechanism of a complement-mediated pseudoallergic reaction.

Intravenous injection of liposomes can cause significant pulmonary hypertension in pigs, a vasoconstrictive response that provides a sensitive model for the cardiopulmonary distress in humans caused by some liposomal drugs. The reaction was recently shown to be a manifestation of "complement activation-related pseudoallergy" (CARPA; Szebeni J, Fontana JL, Wassef NM, Mongan PD, Morse DS, Dobbins DE, Stahl GL, Bünger R, and Alving CR. Circulation 99: 2302-2309, 1999). In the present study we demonstrate that the composition, size, and administration method of liposomes have significant influence on pulmonary vasoactivity, which varied between instantaneously lethal (following bolus injection of 5 mg lipid) to nondetectable (despite infusion of a 2,000-fold higher dose). Experimental conditions augmenting the pulmonary hypertensive response included the presence of dimyristoyl phosphatidylglycerol, 71 mol% cholesterol, distearoyl phosphatidylcholine, and hemoglobin in liposomes, increased vesicle size and polydispersity, and bolus injection vs. slow infusion. The vasoactivity of large multilamellar liposomes was reproduced with human C3a, C5a, and xenoreactive immunoglobulins, and it correlated with the complement activating and natural antibody binding potential of vesicles. Unilamellar, monodisperse liposomes with 0.19 +/- 0.10 microm mean diameter had no significant vasoactivity. These data indicate that liposome-induced pulmonary hypertension in pigs is multifactorial, it is due to natural antibody-triggered classic pathway complement activation and it can be prevented by appropriate tailoring of the structure and administration method of vesicles.

Animals↗

Role of the extracellular matrix and growth factors in skull morphogenesis and in the pathogenesis of craniosynostosis.

The complex and largely obscure regulatory processes that underlie ossification and fusion of the sutures during skull morphogenesis are dependent on the conditions of the extracellular microenvironment. The concept that growth factors are involved in the pathophysiology of craniosynostosis due to premature fusion of skull bone sutures, is supported by recent genetic data. Crouzon and Apert syndromes, for example, are characterized by point mutations in the extracellular or transmembrane domains of fibroblast growth factor-2 receptor. In primary cultures of periosteal fibroblasts and osteoblasts obtained from Apert and Crouzon patients, we observed that Crouzon and Apert cells behaved differently with respect to normal cells as regards the expression of cytokines and extracellular matrix (ECM) macromolecule accumulation. Further modulation of ECM components observed after the addition of cytokines provides support for an autocrine involvement of these cytokines in Crouzon and Apert phenotype. Changes in ECM composition could explain the altered osteogenic process and account for pathological variations in cranial development. We suggest that a correlation exists between in vitro phenotype, clinical features and genotype in the two craniosynostotic syndromes. New research into signal transduction pathways should establish further connections between the mutated genotype and the molecular biology of the cellular phenotype.

Acrocephalosyndactylia↗

Characterization of recombinant human type IX collagen. Association of alpha chains into homotrimeric and heterotrimeric molecules.

As type IX collagen is a minor cartilage component, it is difficult to purify sufficient amounts of it from tissues or cultured cells to study its structure and function. Also, the conventional pepsin digestion used for fibrillar collagens cannot be utilized for purifying type IX collagen, because it contains several interruptions in its collagenous triple helix. A baculovirus expression system was used here to produce recombinant human type IX collagen by coinfecting insect cells with three viruses containing full-length cDNAs for the alpha1(IX), alpha2(IX), and alpha3(IX) collagen chains together with a double promoter virus for the alpha and beta subunits of human prolyl 4-hydroxylase. Correctly folded recombinant type IX collagen was secreted, consisting of the three alpha chains in a 1:1:1 ratio and showing the expected biphasic thermal melting profile. When the individual alpha chains were expressed, disulfide-bonded homotrimers and homodimers of the alpha chains were observed. When the cells were coinfected with the viruses for all three alpha chains, heterotrimers of alpha1(IX), alpha2(IX), and alpha3(IX) were detected in cell culture medium, and the other possible combinations were less prominent. When any two of the alpha chains were co-expressed, in addition to the homodimers and homotrimers, only alpha1(IX) and alpha3(IX) chains were disulfide-bonded. The results thus suggest that the most favored molecular species is an alpha1(IX)alpha2(IX)alpha3(IX) heterotrimer, but the chains are also able to form disulfide-bonded heterotrimers of alpha1(IX) and alpha3(IX) chains and (alpha1(IX))(3), (alpha2(IX))(3), and (alpha3(IX))(3) homotrimers.

Amino Acids↗

A regulatory role of fibroblast growth factor in the expression of decorin, biglycan, betaglycan and syndecan in osteoblasts from patients with Crouzon's syndrome.

Bone development is controlled by the autocrine and/or paracrine effects of regulatory molecules. We previously showed that the phenotype of fibroblasts obtained from patients affected by Crouzon's syndrome, an autosomal dominant disease characterized by pathological skull bone development, differed from that of normal cells and was regulated by interleukin treatments. The changes in the relative concentrations of extracellular macromolecules (glycosaminoglycans-GAG, collagen and fibronectin) were associated with abnormal interleukin secretion that affected the microenvironment where the osteogenic processes take place. Mutations in human fibroblast growth factor receptors are now thought to be involved in Crouzon's syndrome. Since coactivation of interleukins and basic fibroblast growth factor (bFGF) is probably implicated in morphogenetic and osteogenic processes and heparan sulphate proteoglycans have a critical role in regulating bFGF activity, the phenotypes of normal and Crouzon osteoblasts were studied and the effects of bFGF on the expression of bFGF, procollagen alpha1 (I), and proteoglycan (PG) genes for biglycan, decorin, betaglycan and syndecan analyzed. Specific human cDNA probes were used to screen the relative levels of mRNA by Northern analysis. Spontaneous or bFGF-modulated release of interleukins was also assayed. The bFGF gene transcript was detected only in Crouzon osteoblasts. We showed for the first time that Crouzon osteoblasts, despite a mutation in the FGF receptor, still responded to exogenous bFGE In fact, the growth factor induced changes in the GAG profile and in the levels of mRNA coding for PG and procollagen alpha1 (I) and down-regulated heparan sulfate GAG chains. ELISA showed that bFGF-induced interleukin secretion differed in normal and Crouzon osteoblasts. The observed differences in PG core protein, procollagen alpha1 (I) and bFGF could be associated with the Crouzon bone phenotype and also should provide further understanding on the molecular basis of the diseased state of bone.

Adenylyl Cyclases↗

Maintaining abstinence from cigarette smoking: effectiveness of group counselling and factors predicting outcome.

The aim of the study was to assess the effectiveness of worksite group counselling interventions designed to prevent smoking relapse after abstinence has been achieved following 3 months therapy using group support and/or transdermal nicotine replacement therapy. After 3 months, abstinent subjects were randomly allocated either to a counselling group led by professional psychologists (PG), to a counselling group led by former smokers (SG) or to no intervention group (NG). The 3 and 12 months abstinence were defined, respectively, as a sustained smoking cessation during the last month, and the last 9 months. Complete abstinence was confirmed by expired carbon monoxide and by urine cotinine concentrations. The abstinence rate at 3 months was 35.1%. After 12 months abstinence rates were not statistically different in the PG, the SG and the NG (respectively 57.8, 53.4 and 49.6% of those randomised). In multivariate analyzes, baseline variables associated with 12 months abstinence were non-smoking family, gender (male), lower daily intake of nicotine and better psychological adjustment. Mean weight gain at 3 months in abstinent versus relapsed subjects, was respectively, 4.1 and 2.4 kg. Baseline variables associated with weight gain at 3 months were higher Fagerström score, gender (male) and professional status (blue collar worker). Group support after abstinence has been achieved did not significantly improve the abstinence. This study shows the difficulty of preventing smoking relapse with monthly group counselling. The results indicate the need to investigate further specific programmes focusing on factors such as gender, family, nicotine dependence, psychological and weight concerns/issues which may precipitate relapse.

Adolescent↗

TGFbeta isoforms and decorin gene expression are modified in fibroblasts obtained from non-syndromic cleft lip and palate subjects.

Interaction between extracellular matrix (ECM) and cytokines is thought to be crucial for palatal development. The localization of transforming growth factors (TGFalpha and TGFbeta isoforms) in craniofacial tissues suggests that they carry out multiple functions during development. In the present report, we studied TGFalpha, TGFbeta1, and TGFbeta3 expressions and their effects on ECM macromolecule production of normal and cleft palatal fibroblasts in vitro, to investigate the mechanisms by which the phenotypic modulation of fibroblasts occurs during the cleft palate process. The results indicated that, while TGFalpha mRNA was not evidenced in CLP or normal fibroblasts, a reduced TGFbeta1 hybridization signal was detected in CLP fibroblasts. In addition, these secreted more active TGFbeta3 than TGFbeta1, as evaluated in a biological assay. The CLP phenotype, which differed from the normal one because of its higher PG decorin expression and greater production of GAG and collagen, was further modified by the addition of growth factors. In fact, in CLP fibroblasts, TGFalpha and TGFbeta1 down-regulated PG decorin transcript, TGFbeta1 increased collagen and GAG in both cellular and extracellular compartments, and TGFbeta3 promoted secretory processes of cells. In conclusion, the data represent the first report in a human model in vitro that TGFbeta1 and beta3 are differently expressed and are correlated to the CLP phenotype. Thus, strength is given to the hypothesis that TGFbeta isoforms are the potential inducers of phenotypic expression in palatal fibroblasts during development and that an autocrine growth factor production mechanism may be responsible for the phenotypic modifications.

Analysis of Variance↗