The role of selected cell growth factors in the wound healing process

Growth factors, naturally occurring proteins secreted by different cells or tissues, play very important role in accelerating the wound healing process. Growth factors are mainly released from macrophages, neutrophils, lymphocytes, platelets and fibroblasts and induce cells to migrate, divide or produce other factors required for wound healing. These factors bind to target cells via specific cell-surface receptors and may elicit inhibitory or stimulatory responses, depending on interactions with other factors and the cellular environment into which they are liberated. Systemic growth factors, such as growth hormone and local epidermal growth factor, fibroblast growth factor, platelet-derived growth factor, transforming growth factor i and insulin-like growth factor show to enhance wound healing. Growth factors stimulate fibroblasts proliferation and chemotaxis, collagen synthesis, reepithelialization and angiogenesis. Although growth factors are not widely available for clinical use, many are studied actively to determine their role in the acceleration of wound healing. Results of animal experiments and preliminary clinical trials demonstrate that specific uses growth factors may become the new mode of therapy in wound healing process.     

The role of growth factors, cytokines, and vasoactive compounds in obstructive nephropathy

The pre-emptive analgesia concept suggests that pre-administration of analgesics may enhance the efficacy of these drugs. This review has selected the data from the literature according to two types of methodological criteria: Sackett's criteria, and those specific of pre-emptive analgesia studies. Infiltration, spinal and peripheral nerve blocks using local anaesthetic drugs do not seem to produce pre-emptive analgesia. The few positive results have limited clinical significance. The results concerning opioids are contradictory and the clinical significance is limited. Preoperative oral administration of non steroidal anti-inflammatory drugs (NSAIDs) offers no benefit. Intravenous pre-administration has a limited advantage, but enhances perioperative bleeding. Ketamine, an NMDA receptor antagonist, may have some pre-emptive analgesic properties according to the few studies available. In conclusion, pre-administration of analgesic drugs represents the usual strategy for the anaesthesiologist (spinal or peripheral block, infiltration, opioids). In other cases (NSAIDs, ketamine), pre-administration represents a change in usual practice. This is not justified for NSAIDs; NMDA receptor antagonists may offer an interesting research area. Data concerning pre-emptive analgesia for chronic pain syndrome such as phantom limb pain are quite limited.     

Lectin-mediated bioadhesion: binding characteristics of plant lectins on the enterocyte-like cell lines Caco-2, HT-29 and HCT-8

Lipophilic esters of the naturally occurring polyamines putreanine and spermic acid were synthesized, characterized, and modified with nitric oxide to form the corresponding 1-substituted diazen-1-ium-1,2-diolates (previously known as NONOates). The resulting compounds were insoluble in water but were able to release nitric oxide (NO) when placed in phosphate buffered saline (PBS) at physiological pH. The two categories of compounds examined were putreanate esters of cholesterol or hexadecanol, and spermate diesters of cholesterol or hexadecanol. The putreanate NONOate esters of cholesterol and hexadecanol had NO release half-lives of 60 h and 81 h, respectively while the spermate NONOate diesters of cholesterol and hexadecanol and NO release half-lives of 23 days and 7.1 days, respectively. The presence of 5% Tween 20 increased the half-life of the cholesteryl putreanate NONOate to 104 h but only slightly increased the half-life of the hexadecyl putreanate NONOate to 89 h. The 1% presence of the pharmaceutical lung surfactant Survanta did not significantly alter the half-life of NO release for the cholesteryl putreanate NONOate or for the hexadecyl spermeate NONOate, but the surfactant did increase the amount of NO release by 46% and 67% respectively.     

The role of growth hormone and insulin-like growth factors in the immune system

BACKGROUND AND PURPOSE: Understanding the nature and extent of fluctuations in spatial and temporal variables of gait (eg, speed, stride length [SL], stride time [ST]) over the course of the levodopa (L-dopa) cycle of individuals with advanced Parkinson disease (PD) is important in order to assess patients and examine the effectiveness of interventions. The purpose of this study was to determine whether gait variables are sufficiently stable to be used as outcome measures in a clinical trial involving patients with advanced PD. SUBJECTS: Five volunteers (3 male, 2 female; mean age=67.8 years; Hoehn and Yahr stages 3-4) with idiopathic PD of a mean duration of 15.0 years participated. METHODS: Gait speed, SL, and ST were measured as the subjects walked 7.2 m at self-selected speeds. To evaluate the full "on-off" sequence of the L-dopa response, this analysis was repeated 11 times, at intervals of 10% of the L-dopa cycle. Each subject was analyzed on 3 separate days, with approximately 1 month between tests. Two-way repeated-measures analyses of covariance, with 2 within-subject factors (percentage of L-dopa cycle and day) and 1 covariate (height), were applied, and coefficients of variation were calculated to determine the extent of change in speed, SL, and ST over the L-dopa cycle and over the 3 days. RESULTS: The subjects' overall mean gait speed was 70.39 cm/s, representing 55.4% of the age-related normative values. There were no effects of percentage of the L-dopa cycle or day or of the interaction of percentage of the L-dopa cycle and day on speed, SL, and ST. The coefficients of variation for speed and SL were consistently higher than the normative values, ranging from 13.5% to 23.8% and from 13.9% to 23.3% at 20% of the L-dopa cycle, respectively. CONCLUSION AND DISCUSSION: When interpreting spatiotemporal measurements of gait of patients with advanced PD, fluctuations can be extensive and may not follow a predictable pattern.     

Angiogenic factors expressed by human prostatic cell lines: effect on endothelial cell growth in vitro

Using anterograde transport of WGA-HRP and the experimental degeneration method for identification of corticocuneate (CCT) and primary afferent (PAT) terminals in conjunction with gamma-amino butyric acid (GABA) and glutamate immunocytochemistry, this study has demonstrated that the GABA-immunoreactive (GABA-IR) neurons in the rat cuneate nucleus were post-synaptic to PATs (some of them being glutamate-IR), GABA-IR and GABA-negative terminals. The HRP-labelled CCTs did not make any synaptic contacts with GABA-IR neurons but with some GABA-negative dendrites. PATs labelled by HRP or showing degenerating features made direct synaptic contacts with the dendrites of GABA-IR neurons. Beside the above GABA-IR boutons also showed axosomatic and axodendritic synapses with the GABA-IR neurons. In 'triple labeling' method for GABA, PAT and glutamate, it was found that the PATs which were usually glutamate-positive were presynaptic to the dendrites of GABA-IR neurons. Furthermore, some glutamate-IR terminals which were of non-PAT's origin also synapsed with the dendrites and somata of GABA-IR neurons. It is concluded from this study that the major inputs of GABA-IR neurons were from glutamate immunopositive PATs and glutamate terminals of non-PATs origin; other GABA-IR terminals either intrinsic or extrinsic also contributed to the afferent sources of GABA-IR neurons. The CCTs contributed very little, if any, to this input. It is suggested that the PATs and glutamate-IR terminals on GABA-IR neurons may be involved in lateral inhibition for increase of spatial precision. The synaptic contacts between GABA-IR boutons and dendrites or somata of GABA-IR neurons may provide a possible means for disinhibition.     

Determinants of glutamine dependence and utilization by normal and tumor-derived breast cell lines

A continual supply of the amino acid glutamine (GLN) may be necessary for cancerous cell growth. GLN plays a central role in multiple metabolic pathways and has long been considered an essential component of tissue culture media. However, the GLN requirements of tumor cell lines and the factors that determine a cell's need for GLN have not been comprehensively studied. Also, it remains unclear how various metabolic pathways contribute to GLN consumption. In the present study, possible determinants of GLN metabolism were examined in seven breast cell lines, two derived from immortalized normal tissue and five of tumor origin. These cells exhibited different dependencies on media GLN concentration for growth and a wide range of GLN utilization rates. GLN uptake was facilitated by a single, common transporter functionally defined as System ASC. However, the affinities for GLN exhibited by this transporter differed appreciably between cell lines. Furthermore, the concentration at which media GLN became a limiting factor for cellular proliferation correlated with transporter affinity. The origin of the cell lines was not a determinant of GLN metabolism because immortalized cells of nontumor origin exhibited GLN dependence and utilization rates comparable to those of tumor-derived cells. The rates of CO2 production from GLN were similar for each cell lines. Rates of GLN disappearance and glutamate appearance in media were strongly correlated, with 32-80% of media GLN converted to glutamate. Both rates were directly affected by media cystine concentration, suggesting that a large portion of glutamate efflux was coupled with cystine import through the amino acid transport system x(c)-. These results demonstrated that cell growth is a function of GLN influx and suggest that GLN is used to supply glutamate and cystine, perhaps for glutathione synthesis.     

Study of SV40-transformed cell lines from rat dorsolateral prostate--analysis of growth factors and their receptors in the epithelial cell line

The peroxisomal localization of D-aspartate oxidase (EC. 1.4.3.1) was demonstrated in the yeast Cryptococcus humicolus UJ1 cells grown in the medium containing D-aspartate as a nitrogen source. The conclusion is based on the identical behavior of the enzyme with those of peroxisomal marker enzymes, catalase and urate oxidase, during all steps of subcellular fractionations. Supporting evidence was provided by the morphometric analysis of the peroxisomes with electron microscopy, showing that the cells grown on D-aspartate contained more and larger peroxisomes than those grown on L-aspartate, consistent with the 500-fold and 3-fold, higher contents of D-aspartate oxidase and catalase activities, respectively, in the former cells than the latter.     

Transformation by v-Jun prevents cell cycle exit and promotes apoptosis in the absence of serum growth factors

Data was collected about 49 newly diagnosed cases of SSPE in the years 1993-1995 in Poland. In the analyzed period of time a falling of tendency the incidence of SSPE was maintained. Overall incidence--0.42 per million population, was lower than the incidence in years 1990-1992, when it was 0.72. The tendency of a shift towards older age group was maintained--the peak incidence was observed among 19 year olds, as opposed to 15 year olds in the previous analyzed time period. The authors explain the dropping SSPE incidence in Poland with a drop in measales incidence, which is a consequence of growing measles vaccine coverage rates. The influence of a big measles epidemic which occurred in 1989-1990 on a potential rise in number of SSPE cases has not been noted, but further observations are needed.     

Comparative studies of the mitogenic effects of epidermal growth factor and transforming growth factor-alpha and the expression of various growth factors in neoplastic and non-neoplastic prostatic cell lines

Murine acute myeloid leukemia is characterized by chromosome 2 aberrations, and genesis of the marker chromosome 2 by radiation is suspected to be an initiating event of radiation leukemogenesis. A detailed analysis of the type and frequency of chromosome 2 aberrations in murine bone marrow cells at an early stage after irradiation is provided here. A total of 40 male C3H/He mice was exposed to 137Cs gamma-ray at a dose of 1, 2 or 3 Gy, and sacrificed 24 hours after irradiation. Metaphase samples prepared from bone marrow cells were Q-banded for karyotyping or painted with DNA probes specific to chromosome 2. In 5 mice analyzed by karyotyping, one mouse showed high frequency of the marker aberrations as well as other chromosome 2 aberrations. Chromosome painting analysis for the rest of the mice also detected 3 animals showing significantly high frequencies of chromosome 2 aberrations. Dose-dependence of the frequencies was observed even among those mice that tended to be sensitive. The results indicated that there was a subgroup of mice carrying hypersensitive chromosome 2. The subgroup could be leukemia-sensitive if radiation-induced chromosome aberrations are responsible for an early change in myeloid leukemogenesis.     

The role of the nirQOP genes in energy conservation during anaerobic growth of Pseudomonas aeruginosa

The nirQOP operon, which is located between the genes for nitrite reductase and nitric oxide reductase in Pseudomonas aeruginosa, encodes a putative ATP-binding protein and two putative transmembrane proteins. Phylogenetic analysis showed that NirO belongs to the family of subunit III of cytochrome oxidases but is distantly related to the other bacterial or mitochondrial proteins. P. aeruginosa strains that lacked the nirOP genes had all enzyme activities for denitrification and could grow under anaerobic conditions with nitrate or nitrite as an electron acceptor. However, the energy conservation efficiency of anaerobic respiration was lower in these strains than in strains harboring the nirOP gene.     

Autocrine regulation of keratinocytes: the emerging role of heparin-binding, epidermal growth factor-related growth factors

Two hundred and ninety-seven consecutive Charnley total hip replacements that had been followed for at least twenty years or until revision or death were analyzed to determine the effect of early debonding of the smooth-surfaced femoral component on its subsequent survival. Radiographically evident debonding was not found to have a significant effect, with the numbers available, on the long-term survival of the femoral component when the maximum thickness of the radiolucent line between the superolateral border of the prosthesis and the cement had been less than 2.0 millimeters during the first one to five years after the operation. The radiographic finding of debonding also was not found to be associated with pain in the hip. These data show that most components with early debonding functioned well during a long period of follow-up and suggest that debonding of a smooth femoral component of a Charnley total hip replacement should not be considered to be analogous to loosening. In contrast, when the maximum thickness of the radiolucent line between the superolateral border of the prosthesis and the cement was 2.0 millimeters or more, an early appearance of debonding was associated with a significantly poorer (p < 0.0001) probability of survival of the Charnley femoral component without revision because of aseptic loosening. Thus, pronounced early subsidence of the component within the cement mantle had a strong negative impact on the long-term performance of the implant. The results of the present study should not be extrapolated to prostheses with substantially different design characteristics, as it appears that different types of femoral components behave differently when debonding occurs.     

Morphology and serum dependence of cloned cell lines undergoing spontaneous malignant transformation in culture

A number of morphological changes were found to correlate with the occurrence of spontaneous neoplastic transformation in sublines of five rigidly isolated clones of mouse embryo fibroblasts. These morphological changes included increased cytoplasmic basophilia, reduced spreading of cells on the substrate, increased nuclear:cytoplasmic ratio, greater heterogeneity in the size and shape of cells and nuclei, and more random orientation of cells. Because these changes were reproducible, occurring in some sublines of all five clones, they have been described and illustrated to serve as a guide for identifying spontaneous transformants among rodent fibroblasts in culture. Neoplastic transformation was determined by the growth of the cells as malignant neoplasms in syngeneic hosts. The spontaneous transformants, as compared with nonneoplastic fibroblasts derived from the same cell, showed similar saturation densities and serum dependence. Some clones had a higher transformation frequency than the parental line, which remained nonneoplastic for years. Thus, the capacity for continuous growth in vitro can be independent of malignant potential. The use of horse serum as supplement to the medium did not accelerate or increase the frequency of neoplastic transformation.     

The role of the capsular polysaccharide of Aeromonas salmonicida in the adherence and invasion of fish cell lines

The ability of several Aeromonas salmonicida strains grown under different conditions (capsulated and non-capsulated) to adhere to and invade two fish cell lines was compared. The level of adherence was slightly higher when the strains were grown under conditions promoting capsule formation than when the same strains were grown under conditions which did not promote capsule formation. However, the most significant difference among the wild-type strains grown under conditions promoting capsule formation was the ability to invade fish cell lines, which was significantly higher than when the same strains were grown under conditions which did not promote capsule formation. From these results we conclude that the capsular polysaccharide, in these strains, is an important factor for intracellular invasion.     

Role of fibroblast growth factors and their receptors in mouse primordial germ cell growth

Primordial germ cells (PGCs) are the embryonic progenitors of mature germ cells. During their proliferative stage, murine PGCs may be transiently cultured on mitotically inactive feeder layers. This culture system has permitted identification of several growth factors active toward PGCs. We and others have previously identified basic fibroblast growth factor (bFGF) as a powerful mitogen in this system. Here we characterize some of the functions of bFGF in PGC culture. Our data demonstrate that fibroblast growth factor (FGF) receptors I and II are present in the developing gonad and are consistent with expression of these receptors by PGCs. Moreover, PGCs can bind radiolabeled bFGF in vitro, demonstrating that the factor can act directly on these cells. While mitotic PGCs of either sex are shown to bind radiolabeled bFGF, oogonia that are undergoing meiotic arrest exhibit reduced bFGF binding, indicating potential developmental regulation of an FGF receptor.     

Differential sensitivity of human neuroblastoma cell lines to ethanol: correlations with their proliferative responses to mitogenic growth factors and expression of growth factor receptors

Early ethanol exposure depletes neurons in the developing nervous system, however the effects on neuronal precursors are not homogeneous. Some cells are more susceptible to ethanol toxicity than others. Growth factors are important mitogens for neuronal precursors. We tested the hypothesis that the differential sensitivity of neuronal precursors to ethanol is determined by their responses to growth factors using an in vitro model (SH-SY5Y, SK-N-SH, and IMR32 neuroblastoma cells) of neuronal precursors. The three cell lines were raised in a medium containing 10% or 0% fetal calf serum. Cells were exposed to ethanol and/or a growth factor. These factors included basic fibroblast growth factor, epidermal growth factor, insulin-like growth factor-I, nerve growth factor, and platelet-derived growth factors AA and BB. The numbers of cells per culture were counted both before and after 3 days of ethanol and/or growth factor treatment. In addition, the effect of ethanol exposure on the expression of receptors for these growth factors was examined. Neuroblastoma cells displayed differential sensitivity to ethanol. The growth of SH-SY5Y and SK-N-SH cells was inhibited by ethanol in a concentration-dependent manner. Ethanol did not affect cell viability. Thus, this inhibition resulted from a reduction of cell proliferation. In contrast, IMR32 cells were not affected by ethanol (even at concentrations as high as 800 mg/dl). The response to growth factors was also heterogeneous. In serum-supplemented medium, SH-SY5Y and SK-N-SH cells were stimulated by all of the tested growth factors. For cells raised in a serum-free medium, only the nerve growth factor was ineffective. IMR32 cells, however, were unaffected by most of these growth factors, regardless of the medium conditions. Ethanol blocked the action of all growth factors tested. In general, all cells expressed the specific receptors for the six growth factors. Only the expression of the basic fibroblast growth factor, insulin-like growth factor-I, and nerve growth factor receptors were reduced by ethanol exposure. In summary, neuroblastoma cells exhibit differential susceptibility to ethanol, and this correlates with their response to mitogenic growth factors. Some growth factors are a target of ethanol toxicity. These heterogeneous effects seem to parallel ethanol-induced changes of proliferating neuronal precursors in vivo.