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PubMed2006

Neonatal meningitis: what is the correlation among cerebrospinal fluid cultures, blood cultures, and cerebrospinal fluid parameters?

BACKGROUND: Meningitis is a substantial cause of morbidity and mortality in neonates. Clinicians frequently use the presence of positive blood cultures to determine whether neonates should undergo lumbar puncture. Abnormal cerebrospinal fluid (CSF) parameters are often used to predict neonatal meningitis and determine length and type of antibiotic therapy in neonates with a positive blood culture and negative CSF culture. METHODS: We evaluated the first lumbar puncture of 9111 neonates at > or =34 weeks' estimated gestational age from 150 NICUs, managed by the Pediatrix Medical Group, Inc. CSF culture results were compared with results of blood cultures and CSF parameters (white blood cells [WBCs], glucose, and protein) to establish the concordance of these values in culture-proven meningitis. CSF cultures positive for coagulase-negative staphylococci and other probable contaminants, as well as fungal and viral pathogens, were excluded from analyses. RESULTS: Meningitis was confirmed by culture in 95 (1.0%) neonates. Of the 95 patients with meningitis, 92 had a documented blood culture. Only 57 (62%) of 92 patients had a concomitant-positive blood culture; 35 (38%) of 92 had a negative blood culture. In neonates with both positive blood and CSF cultures, the organisms isolated were discordant in 2 (3.5%) of 57 cases. In each case, the CSF pathogen required different antimicrobial therapy than the blood pathogen. For culture-proven meningitis, CSF WBC counts of >0 cells per mm3 had sensitivity at 97% and specificity at 11%. CSF WBC counts of >21 cells per mm3 had sensitivity at 79% and specificity at 81%. Culture-proven meningitis was not diagnosed accurately by CSF glucose or by protein. CONCLUSIONS: Neonatal meningitis frequently occurs in the absence of bacteremia and in the presence of normal CSF parameters. No single CSF value can reliably exclude the presence of meningitis in neonates. The CSF culture is critical to establishing the diagnosis of neonatal meningitis.

Bacteremia↗
PubMed2000

Transforming cultural competence into cross-cultural efficacy in women's health education.

To prepare students to be effective practitioners in an increasingly diverse United States, medical educators must design cross-cultural curricula, including curricula in women's health. One goal of such education is cultural competence, defined as a set of skills that allow individuals to increase their understanding of cultural differences and similarities within, among, and between groups. In the context of addressing health care needs, including those of women, the author states that it is valid to define cultural groups as those whose members receive different and usually inadequate health care compared with that received by members of the majority culture. The author proposes, however, that cross-cultural efficacy is preferable to cultural competency as a goal of cross-cultural education because it implies that the caregiver is effective in interactions that involve individuals of different cultures and that neither the caregiver's nor the patient's culture offers the preferred view. She then explains why cross-cultural education needs to expand the objectives of women's health education to go beyond the traditional ones, and emphasizes that learners should be trained in the real-world situations they will face when aiding a variety of women patients. There are several challenges involved in both cross-cultural education and women's health education (e.g., resistance to learning; fear of dealing openly with issues of discrimination; lack of teaching tools, knowledge, and time). There is also a need to assess the student's acquisition of cross-cultural efficacy at each milestone in medical education and women's health education. Components of such assessment (e.g., use of various evaluation strategies) and educational objectives and methods are outlined. The author closes with an overview of what must happen to effectively integrate cross-cultural efficacy teaching into the curriculum to produce physicians who can care effectively for all their patients, including their female patients.

Attitude of Health Personnel↗
PubMed2006

Introduction. Back to nurture: cross-cultural research as a paradigm for understanding bio-cultural dynamics of cognitive ageing.

BACKGROUND: One of the earliest and most persistent inquiries in developmental psychology is that of the relative contributions of nature and nurture to human ontogeny. One way of studying this distinction is by doing cross-cultural studies, in which culture provides a powerful way to operationalize the influence of nurture. OBJECTIVE: The purpose is to provide some background to the emergence of the field of cross-cultural gerontological research, as a prelude to the special series of papers on cognitive ageing and culture from the laboratory of Park and Nisbett and their colleagues. METHODS: A qualitative review of theoretical notions about cross-cultural differences provides an introduction and orientation to papers dealing with aspects of cognitive ageing, including picture naming specificity, source memory, use of categorical information in free recall, and perceptions of stereotypes of older and younger adults. RESULTS: Most of the research on cognitive ageing has focused on Western cultures and has assumed universality in the operation of the cognitive system. If culture makes a difference, a plausible hypothesis might be that, with ageing, any effects of culture on cognitive processes would become more apparent, due to older adults' increased exposure to their culture, and that these might be limited to the pragmatics of intelligence or crystallized abilities. The papers presented demonstrate that for some cognitive processes, i.e., source memory and free recall, cultural invariance, or universality of cognitive ageing, was observed. Further, stereotypes of both cultures shifted with advancing age from positive to increasingly negative views for mental and physical domains. A modest interaction of age and culture was observed in social and emotional domains, where stereotypes were relatively neutral, except for a small positive bias among the young Chinese participants for both older and younger adults. Marked cultural differences were seen in naming specificity and in the use of categories to structure the recall process. CONCLUSIONS: Claims have been made about universals of cognitive function, particularly for basic cognitive processes. These results challenge that view. Cross-cultural research has begun to reshape the way we think about cognitive ageing.

Adult↗
PubMed2001

Comparative analysis of proteoglycans synthesized by chick corneal stromal cells in cell culture and organ culture.

Proteoglycans (PGs) synthesized by chick corneal stromal cells in cell culture and organ culture were metabolically radiolabelled with [35S]sulfate (for glycosaminoglycans) and [3H]leucine (for core proteins). Media, cell extracts and organ extracts from cultures were chromatographed on DEAE-Sephacel columns and separated into three fractions: the pass-through fraction (Fraction 1: nonsulfated PGs, hardly sulfated PGs, or glycoproteins with some oligosaccharides), the fraction eluted with a low salt concentration (Fraction 2: undersulfated PGs), and the fraction eluted with a high salt concentration (Fraction 3: highly sulfated PGs). The PG compositions of each fraction of cell culture and organ culture were then compared. While the proportions of highly sulfated KSPG in Fractions 3 of medium and cell extract of cell culture were both very low compared with those of medium and organ extract of organ culture, respectively, the proportions of highly sulfated CS/DS PG in Fractions 3 of those of cell culture were higher than those of organ culture. On the other hand, the proportions in the 35S activities of nonsulfated or undersulfated KSPG in Fractions 1 and 2 of medium and cell extract of cell culture were comparable to those of organ culture. Furthermore, the proportions of core proteins of undersulfated KSPG in Fractions 2 were higher in cell culture than in organ culture. These results show that, when the cells are cell-cultured, the degree of sulfation of KS chains decreases markedly, but the syntheses of the glycosaminoglycan backbone and core protein are maintained.

Animals↗
PubMed2004

[Effect of delay of blood cultures on positive detection by automated blood culture system].

The effect of entry delayed blood culture bottles until the start of incubation for mechanical detection of organism were compared using 2 major blood culture systems; BACTEC 9240 system and BacT/ALERT 3D system. Total of 13 bacterial strains; 5 gram-positive cocci, 7 gram-negative bacilli and Candida parapsilosis which were isolated mainly from blood cultures were used as the test strains. BACTEC 92F, 93F and BacT/ALERT FA, FN bottles were used as the blood culture bottles. All the bottles inoculated with the test strains were incubated and evaluated immediately after standing at room temperature for 24, 42, 48, 54 or 72 hours, using the respective automated blood culture systems. All the bottles were subcultured. The effect of entry delay the blood culture bottles for the mechanical detection was observed in many gram-negative organisms in BACTEC 9240 system. The blood cultures were evaluated not to be positive in 4 of the 10 samples on delaying for 24 hours or in any of the samples on delaying for 42 hours in the BACTEC 92F bottles inoculated with Escherichia coli. In Serratia marcescens, the blood cultures were evaluated not to be positive in 5 of the 10 samples on delaying for 24 hours or in any of the samples on delaying for 42 hours in the BACTEC 92F bottles. In Klebsiella pneumoniae, the blood cultures were evaluated not to be positive in 9 of the 10 samples on delaying for 42 hours. In Enterococcus faecalis, Pseudomonas aeruginosa and Proteus mirabilis, the blood cultures were evaluated not to be positive in 5-6 of the 10 samples on delaying for 42 hours. On the other hand, the blood cultures were evaluated to be positive in most of the samples of Acinetobacter calcoaceticus (except 3 of the 10 samples which were evaluated not to be positive) on delaying for 42 hours in BacT/ALERT 3 D system. The samples except part of Streptococcus spp. were detected by subculture in both the bottles. These results indicate that the delayed time of blood culture bottles before inoculation with the test bacterial samples affects the positive detection of blood cultures markedly in the blood culture system. Therefore, the immediate incubation was considered to be necessary.

Blood↗
PubMedDate not supplied

Cultured porcine urinary bladder epithelial cells as a screening model for genotoxic effects of aromatic amines: characterisation and application of the cell culture model.

Isolated epithelial cells from porcine urinary bladders were maintained in dividing long-term monolayer cultures, and were used as a model system for the urinary bladder in toxicological studies in vitro. To examine the state of differentiation during the culture period, the culture system was characterised morphologically by light and transmission electron microscopy and by immune fluorescence labelling with antibodies against cytokeratins 7,13 and pan. The cultured cells were identified as urothelial epithelium by their polarised structure, and by their expression of several uroepithelial specific morphological features, such as fusiform vesicles, tight junctions and an asymmetric apical cell membrane. Additionally, the cells were labelled with anti-cytokeratin 7,13 and pan antibodies, and negatively with anti-vimentin antibodies. The maintenance of suitable culture conditions was shown by the stable enzyme activities of (gamma-glutamyltranspeptidase, alkaline phosphatase and acid phosphatase over a culture period of 4 weeks. A good viability of the cultured cells under the chosen culture conditions was shown by the presence of low amounts of lactate dehydrogenase (< of = 5%) in the culture medium. The activities of the chosen marker enzymes for cell differentiation (gamma-glutamyltranspeptidase), lysosomes (acid phosphatase) and luminal membranes (alkaline phosphatase) were relatively stable over the observed culture period. Enzyme activities involved in metabolism of xenobiotics were determined, to define the ability for metabolism in cultured cells compared with bladder tissue in situ. Several constitutive phase I and II enzyme activities were found to be stable during the culture period, indicating that the cultured cells should be able to metabolise xenobiotics in a comparable manner to the urothelium in vivo. The cytotoxic effects of xenobiotics were investigated and IC50 values were determined by means of lactate dehydrogenase leakage and inhibition of neutral red uptake. The induction of sister chromatid exchanges was used as a parameter for the genotoxic effects of several xenobiotics. This cell culture system was found to be a very good screening system for the testing of substances that affect the bladder, especially aromatic amines.

Amines↗
PubMed2000

Beyond cultural competence: a model for individual and institutional cultural development.

Nursing's attention to cultural diversity has been influenced by the changing demographic composition of the U.S. population. Nursing must continue to increase awareness and promote attitudinal and behavioral changes that will result in the delivery of culturally appropriate nursing care. The nursing literature includes several models of cultural development to assist nurses and other health care professionals in conducting a cultural assessment and incorporating cultural data into nursing care plans. This article presents a synthesis model of cultural development that illustrates that cultural awareness, cultural sensitivity, and cultural competence do not achieve the level of cultural development necessary to meet the health care needs of a diverse population. Cultural proficiency is a concept that extends cultural competence into nursing practice, administration, education, and research. It is a philosophical and behavioral approach to cultural diversity that guides and prescribes individual and institutional behavior toward "cultural others."

Community Health Nursing↗
PubMed1991

Modulations of the epithelial phenotype and functional activity of cultured bovine tracheal gland cells: dependence on the culture medium and passage number.

Bovine tracheal gland (BTG) cells in culture show an epithelial-fibroblastoid transition after several passages. To investigate these BTG cell phenotype changes, we studied the effects of both the culture medium and passage number on the expression of epithelial cytoskeletal proteins and glandular serous cell markers. We also analyzed the intracellular cAMP level in the basal state and after adrenergic stimulation. Three culture media were used: 1) serum-free defined medium (SFDM); 2) medium supplemented with 2% Ultroser G; and 3) medium supplemented with 10% fetal calf serum (FCS). Using immunofluorescence microscopy, we showed that, in the first 4 passages whatever the culture conditions, BTG cells expressed immunoreactivities to cytokeratin filaments and desmoplakins I and II, whereas vimentin filaments were not detected. After four passages, BTG cells cultured in 10% FCS or 2% Ultroser G became progressively fibroblastoid and showed immunoreactivities to both vimentin and cytokeratin intermediate filaments. No immunoreactivity to vimentin filaments was observed on BTG cells cultured in a SFDM. Using biochemical analysis, we showed that basal levels of cAMP in cultured BTG cells and lysozyme secretion by these cells vary according to the culture medium and passage number. It was higher in BTG cells cultured in a SFDM compared to that recovered from cells cultured in medium supplemented with Ultroser G or FCS. Whatever the culture medium, BTG cells responded to stimulation by isoproterenol. However, the results of stimulation in a SFDM were higher than in Ultroser G or FCS supplemented medium. We conclude that the BTG epithelial cell organization and the regulation of biosynthesis of secretory proteins by these cells in culture depend on both the culture medium and passage number.(ABSTRACT TRUNCATED AT 250 WORDS)

1-Methyl-3-isobutylxanthine↗
PubMed2002

Application of alginate three-dimensional culture system for in vitro culture of mandibular condylar chondrocytes from human osteoarthritic temporomandibular joint.

OBJECTIVE: To evaluate the use of alginate three-dimensional culture system for mandibular condylar chondrocytes culture in vitro from human osteoarthritic temporomandibular joint. METHODS: The cultured mandibular condylar chondrocytes from the operatively removed cartilage from a patient with osteoarthritic temporomandibular joint were harvested by mechanical dissection and enzyme digestion. Partial chondrocytes were suspended in the aqueous sodium alginate beads with high seeding density and cultured for 4 weeks, while the others were cultured in monolayer culture condition for 1 week. Thereafter, the alginate beads were embedded in paraffin and sectioned, then studied immunologically with type II collagen antibody and aggrecan antibody, same studies were adopted for the monolayer cultures. RESULTS: The monolayer cultures were confirmed as chondrocytes. The chondrocytes cultured in the alginate medium showed well. These cells exhibited the excellent differentiated phenotype after 4 weeks culture in alginate gel. CONCLUSIONS: The condylar chondrocytes from human osteoarthritic temporomandibular joint were successfully cultured in vitro. The alginate three-dimensional culture system was successfully adopted for in vitro culture of condylar chondrocytes from human osteoarthritic temporomandibular joint, in which the chondrocytes exhibited the excellent differentiated phenotype.

Cartilage, Articular↗
PubMed1993

Ultrastructural morphology of immature mast cells in sequential suspension cultures of human cord blood cells supplemented with c-kit ligand; distinction from mature basophilic leukocytes undergoing secretion in the same cultures.

The ability to culture human mast cells and, thus, to determine their ontogeny and possible relationships to other lineages has been facilitated by new studies using cocultures of cord blood cells with mouse fibroblasts and recombinant human or murine c-kit ligand-supplemented suspension cultures of cord blood cells. In this study, we examined c-kit ligand-supplemented cord blood cell suspension cultures designed so that the effects of growth factor source, individual cord sample, and culture time (3-17 weeks) on the developing mast cell lineage could be individually evaluated. We found that human mast cells, basophils, neutrophils, eosinophils, macrophages, megakaryocytes, and endothelial cells were present in these cultures. The numbers of mast cells and their granules increased with culture time; mature basophils, present in quantity in 3-week cultures, decreased in number and released granule contents with increased culture times. The mast cell lineage developed similarly, regardless of which factor preparation was added to cultures, but considerable variability existed among individual donors from whom cord bloods were obtained. Unlike the mature, crystal-containing mast cells that regularly developed in fibroblast cord blood cocultures (Furitsu et al. [1989] Proc. Natl. Acad. Sci. USA 86, 10039-10043), human mast cells failed to attain full maturity in the suspension cultures examined here, regardless of individual cord sample, added growth factor, or culture time. Furthermore, unlike cells of the basophil lineage in which granule content release was regularly observed, morphologic evidence of secretion from human mast cells was absent. Instead, these cells were actively undergoing granule building as determined by the increasing numbers of granules and filling of these containers over culture time. Crystal granules never developed, even at the maximum culture time of 17 weeks. We conclude that fibroblasts are necessary and sufficient for the differentiation and maturation of human mast cells in vitro from their agranular precursors in cord blood but that soluble c-kit ligand is not.

Animals↗
PubMed1986

Culture duration alters the glutathione content and sensitivity to ethacrynic acid of rat hepatocyte monolayer cultures.

Many of the differentiated functions of hepatocytes are lost in culture, yet addition of certain medium supplements can aid in the retention of differentiated character. Therefore, the effect of time in monolayer culture on rat hepatocyte glutathione (GSH) synthesis and sensitivity to the GSH detoxicated xenobiotic ethacrynic acid was examined in cultures with and without medium supplementation by transferrin and sodium selenite. GSH content was found to be about 12 nmol/micrograms DNA at 4 hr in culture and to approximately triple by 24 hr. Intracellular GSH levels continued to increase in transferrin/sodium selenite-supplemented cultures, from 32 to 41.6 nmol/micrograms DNA, while GSH levels in unsupplemented cultures declined to 18 nmol/micrograms DNA. However, the rate of GSH synthesis after diethylmaleate depletion was found to decrease from 4.2 to 2.8 nmol/hr/micrograms DNA at 4 and 24 hr after inoculation, respectively. GSH repletion rate increased to 3.9 nmol/hr/micrograms DNA at 48 hr. The GSH accumulation rate after depletion in supplemented cultures did not vary significantly over the initial 48 hr. Incubation for 3 hr with 100 microM ethacrynic acid (EA) did not elicit an increase in LDH leakage in hepatocyte monolayers after 4 or 48 hr in culture or in cultures with supplemented medium at any time point tested. Cultures 24 hr in medium without transferrin/sodium selenite supplementation exhibited significant LDH leakage after 3 hr of EA treatment. Over the 3 hr EA treatment, intracellular GSH content was decreased in all cultures. Only in the 24 hr unsupplemented cultures did GSH depletion exceed the 90% level previously associated with depletion of the mitochondrial pool of GSH and EA toxicity in hepatocytes. The experiments show that during the redifferentiation of hepatocytes in culture, a transient period occurs when apparent GSH synthesis is depressed and enhanced sensitivity to GSH-detoxicated compounds is observed. This period of increased sensitivity is prevented or at least delayed by inclusion of supplemental transferrin and sodium selenite, suggesting that redifferentiation can be regulated by extracellular influences.

Animals↗
PubMed1993

A developmental study of lactate dehydrogenase isozyme and aspartate aminotransferase activity in organotypic rat hippocampal slice cultures and primary cultures of mouse neocortical and cerebellar neurons.

The development of enzyme activity and isozyme distribution of lactate dehydrogenase (LDH) was studied in murine organotypic hippocampal slice cultures and dissociated cultures of neocortical neurons and cerebellar granule cells and compared with that of the respective brain regions in vivo. In the hippocampal slice cultures and the hippocampus in vivo, the activity of aspartate aminotransferase (AAT) was also measured. During development in culture the specific activity of LDH increased in all types of cultures reaching values similar to that found in the corresponding brain areas in vivo. However, significant differences in the isozyme distribution were observed between the preparations in vitro and in vivo. During development in vivo, the LDH isozyme pattern changed from a preferential M-subunit composition to a preferential H-subunit composition regardless of the brain area. This shift was not observed in the respective cultures where the M4-isozyme prevailed at all culture periods examined accounting for 30-45% of the total LDH activity. The cultured cerebellar granule cells did not express the H4-isozyme at all, while in the hippocampal slice cultures and the cultured neo-cortical neurons this isozyme accounted for about 5% of the total LDH activity. The activity of AAT in the hippocampal organotypic slice cultures increased considerably during the culture period in parallel with the increase in AAT activity during postnatal development of hippocampus in vivo. The activity of AAT in the slice cultures was, however, consistently lower than the corresponding activity in vivo.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed2006

A biocompatible micro cell culture chamber (microCCC) for the culturing and on-line monitoring of eukaryote cells.

We have previously shown that a polymeric (PMMA) chip with medium perfusion and integrated heat regulation provides sufficiently precise heat regulation, pH-control and medium exchange to support cell growth for weeks. However, it was unclear how closely the cells cultured in the chip resembled cells cultured in the culture flask. In the current study, gene expression profiles of cells cultured in the chip were compared with gene expression profiles of cells cultured in culture flasks. The results showed that there were only two genes that were differently expressed in cells grown in the cell culture chip compared to cell culture flasks. The cell culture chip could without further modification support cell growth of two other cell lines. Light coming from the microscope lamp during optical recordings of the cells was the only external factor identified, that could have a negative effect on cell survival. Low grade light exposure was however compatible with optical recordings as well as cell viability. These results strongly indicate that a cell culture chip could be constructed that allowed for on-line optical recording of cellular events without affecting the cell culturing condition compared to cell cultured in culture flasks incubated in a dark and CO2 conditioned incubator.

Caco-2 Cells↗
PubMed1998

Clinical and laboratory spectrum of culture-proven human granulocytic ehrlichiosis: comparison with culture-negative cases.

We describe the clinical and laboratory manifestations of human granulocytic ehrlichiosis (HGE) in eight patients for whom cultures were positive for the HGE agent and compare them with 15 patients for whom cultures were negative but who fulfilled a modified New York State Surveillance definition for HGE. Polymerase chain reaction analysis was positive in 8 (100%) of 8 culture-positive cases vs. 3 (20%) of 15 culture-negative cases (P < .001), morulae were detected in 7 (100%) of 7 culture-positive cases in which tests were performed vs. 0 of 15 culture-negative cases (P < .001), and a fourfold change in antibody titer was demonstrated in 6 (75%) of 8 culture-positive cases vs. 9 (69%) of 13 culture-negative cases (P = not significant). Patients for whom cultures were positive had higher mean oral temperatures +/- SD at presentation than did patients for whom cultures were negative (38.6 degrees C +/- 0.7 degree C vs. 37.2 degrees C +/- 0.8 degree C, respectively; P = .002). Other symptoms and signs were not significantly different between the two groups. Multivariate analysis revealed that the lymphocyte count at presentation was significantly lower in culture-positive cases than in culture-negative cases. Clinical response to treatment was similar in the two groups. Culture confirmation of HGE is the gold standard for defining the sensitivity and specificity of other diagnostic tests presently being developed.

Adult↗
PubMed1987

Characterization of fetal human brain cultures. Development of a potential model for selectively purifying human glial cells in culture.

Seven fetal human brain and three fetal human leptomeningeal cultures were characterized according to cell morphology, ultrastructural features, antigen expression, and collagen biosynthesis capabilities. Primary cultures derived from mechanically and enzymatically dissociated samples of fetal human brain consisted of a heterogeneous cell population in which astrocytes, oligodendrocytes, neurons, mesenchymal (leptomeningeal) cells, and macrophages were identified by light and electron microscopy. With progressive subcultivation, a homogeneous, leptomeningeal cell-derived population predominated. Fetal human brain and leptomeningeal specimens embedded in paraffin were analyzed immunohistochemically for the distribution of glial fibrillary acidic protein (GFAP), vimentin, factor-VIII-related antigen, fibronectin, laminin, type IV collagen, and procollagen III. Only GFAP and vimentin identified astrocytes and radial glia in the developing human brain; fibronectin, laminin, and the collagen types were immunolocalized largely to the leptomeninges and to the cerebral vasculature. The percentage of cells positively identified by antiserum to GFAP was greatest in primary cultures of fetal human brain; by the fourth passage, none of the fetal brain cultures were GFAP positive. The progressive decrease in the percentage of GFAP-positive cells was accompanied by an increase in the percentage of cells identified by collagen immunomarkers. Furthermore, in double immunolabeling experiments, antibodies to GFAP recognized a population of cells that was not identified by antibodies to laminin, fibronectin, type IV collagen, or procollagen III. SDS-PAGE and DEAE-cellulose chromatography of [3H]-proline-labeled early-passage fetal human brain cultures revealed collagen profiles identical to those obtained from direct cultures of the leptomeninges. The characteristics of later-passage fetal human brain cultures were identical in all respects to those of the fetal human leptomeningeal cultures. The proliferation of leptomeningeal cells could be inhibited by exposing the cells to cis-hydroxyproline (200 micrograms/ml). Primary fetal human brain cultures similarly treated with the proline analogue were found to be highly enriched for glial cells; these cultures were more than 90% GFAP positive. We conclude that primary fetal human brain cultures consist of a heterogeneous population of cells, most of which under the present culture conditions can be identified as glial cells. Subcultivation of human fetal brain cultures results in the overgrowth of mesenchymal cells, which are presumably derived from the leptomeninges.(ABSTRACT TRUNCATED AT 400 WORDS)

Brain↗
PubMed1998

Thyroid hormone excess increases insulin-like growth factor I transcripts in bone marrow cell cultures: divergent effects on vertebral and femoral cell cultures.

Thyroid hormones (T3 and T4) regulate bone development, growth, and turnover. Studies have suggested that different skeletal sites respond differently to thyroid hormones. Therefore, we examined the in vitro T3 responsiveness of cells committed to the osteoblast lineage as a function of skeletal location. Bone marrow cells derived from female rat femurs and vertebrae were cultured using conditions that induce osteogenic differentiation. Cells from both sites formed mineralized bone nodules in primary and secondary culture. In femoral cultures, collagen type I (coll I) and osteocalcin (OC) messenger RNA (mRNA) levels increased from the earliest time point examined (day 3) to a maximum on day 12 and thereafter declined to undetectable levels. T3 increased both OC and coll I mRNA, resulting in a continuous expression throughout the culture period. Insulin-like growth factor I (IGF-I) gene expression was detected at very low levels by Northern analysis of femoral total RNA, and T3 only marginally enhanced IGF-I mRNA levels. In vertebral cultures, OC and coll I mRNA levels also increased with time in culture, but remained expressed throughout the culture period. OC and coll I mRNA levels were not markedly altered in response to T3. In contrast to femoral cells, IGF-I gene expression was easily visualized in Northern blots from untreated vertebral cultures and was markedly increased by the addition of T3. The continuous presence of T3 (10(-7) M) in the medium for 18 days caused a marked decrease in the number of alkaline phosphatase-positive colonies formed in femoral secondary cultures, but only a slight decrease in the number in vertebral cultures. In addition, short term (6 days) exposure to T3 (10(-7) M) at the beginning of the culture period decreased alkaline phosphatase activity in femoral cultures, but not in vertebral cultures. These findings indicate that there are skeletal site-dependent differences in the in vitro responses of cells of the osteoblastic lineage to thyroid hormone.

Alkaline Phosphatase↗
PubMedDate not supplied

Culture conditions dictate protease and tannase production in submerged and solid-state cultures of Aspergillus niger Aa-20.

Undesirable protease production by Aspergillus niger Aa-20 in submerged culture and solid-state culture was evaluated using different concentrations of tannic acid as sole carbon source in a model system designed for tannase production. Protease production was found to be dependent on the culture system used (submerged culture or solid-state culture) and on the initial tannic acid concentration. Expression of protease activity in submerged culture was higher (up to 10 times) than activity obtained in solid-state culture, using identical culture medium composition. In submerged culture, the lowest final protease activity (0.13 IU) was obtained with the highest tannic acid concentration, while in solid-state culture protease activity was not affected by changes in initial substrate concentration. Absence of detectable proteolytic activity in solid-state culture is related to high production of tannase enzyme. Hence, the use of solid-state culture for fungal enzyme production may allow for higher and more stable enzyme titers present in culture extracts.

Aspergillus niger↗
PubMed2005

Cell cycle effects of radiation on human bronchial epithelium and lung carcinoma cells in monolayer cultures and a three-dimensional co-culture system.

The aim of this study was to investigate whether the three-dimensional structure of the bronchial tissue and the contact of non-malignant with malignant cells influence the effectiveness of radiotherapy. Monolayer cultures of cells of the human bronchial epithelial cell line BEAS 2B, monolayer co-cultures of BEAS 2B cells and cells of the GFP-transfected lung carcinoma cell line EPLC 32M1, organ cultures of human bronchial epithelium, and organ co-cultures with EPLC 32M1 cells were irradiated with 10 Gy, and the DNA content was analyzed using flow cytometry. In non-malignant epithelial cells, BEAS 2B monolayer cultures without tumor cells were highly radiosensitive. However, contact with tumor cells in monolayer co-cultures markedly reduced radiosensitivity. Non-malignant cells in three-dimensional organ cultures and organ co-cultures with tumor cells showed moderate radiosensitivity. In EPLC 32M1 tumor cells, proliferation was increased without irradiation when the cells were in contact with epithelial cells in both organ and monolayer co-cultures. Radiosensitivity was higher in organ co-cultures than in monolayer cultures and monolayer co-cultures. These data indicate that organ co-cultures in combination with flow cytometry allow investigation of the effects of radiation in an in vivo-like environment and that both the spatial organization and the interaction of non-malignant and tumor cells are crucial for the effectiveness of radiotherapy.

Bronchi↗