Biomedical subjects

D Li

Publications and source records attributed to D Li.

At least 541 records · Page 30Linked to original sources

PubMed1997

Electrokinetic Effects on Pressure-Driven Liquid Flows in Rectangular Microchannels

The effects of the electrical double layer near the solid-liquid interface and the induced electrokinetic field on the pressure-driven liquid flow through a rectangular microchannel are analyzed in this work. A nonlinear, two-dimensional Poisson-Boltzmann equation governing the electrical double layer field in the cross section of rectangular channels is numerically solved with the use of a finite-difference scheme. A body force caused by the electrical double field and the flow-induced electrokinetic field is considered in the equation of motion. An exact solution to this equation of motion in rectangular microchannels is obtained by employing the Green function formulation. The effects of the ionic concentration of the liquid, the zeta potential of the solid surface, and the size and the shape of microchannels on the fluid velocity distribution, streaming potential, volumetric flow rate, friction coefficient, and apparent viscosity are discussed. The results clearly show that for a liquid solution of low ionic concentration and a solid surface of high zeta potential the liquid flow in rectangular microchannels is significantly influenced by the presence of the electrical double layer field and hence deviates from the flow characteristics described by classical fluid mechanics. Copyright 1997 Academic Press. Copyright 1997Academic Press

Journal Article↗

PubMed1997

Transforming growth factor-alpha stimulates insulin-like growth factor binding protein-4 (IGFBP-4) expression and blocks follicle-stimulating hormone regulation of IGFBP-4 production in rat granulosa cells.

The ability of TGF-alpha to regulate insulin-like growth factor binding protein-4 (IGFBP-4), was investigated. Primary cultures of rat granulosa cells (GC) were grown in serum-free medium with rat (r) TGF-alpha and/or rFSH, and secreted IGFBP-4 protein and its steady state mRNA levels were measured by Western immunoblotting and Northern blotting, respectively. Control (untreated) cells secreted IGFBP-4 spontaneously, and the levels were increased by rTGF-alpha in a dose- and time-dependent manner. rTGF-alpha abolished FSH-induced IGFBP-4 protease activity and suppressed FSH-dependent effects on IGFBP-4 production. IGFBP-4 mRNA levels were decreased and increased by FSH and TGF-alpha, respectively, and TGF-alpha blocked the FSH effects. These results demonstrate that TGF-alpha is a potent stimulator of IGFBP-4 expression in rat GC and can overcome the regulatory effects of FSH on IGFBP-4 production. The consequence of these TGF-alpha effects is a marked, sustained increase in the levels of IGFBP-4 in the microenvironment.

Animals↗

PubMed1997

Cloning and expression of cDNA encoding a mitogen-activated protein kinase from a phytopathogenic filamentous fungus.

We have cloned a mitogen-activated protein kinase (MAPK) designated Fusarium solani f. sp. pisi mitogen-activated protein kinase (FsMAPK) from the phytopathogenic filamentous fungus F. solani f. sp. pisi T8 strain. A single open reading frame (ORF) of 1068 bp encoding a polypeptide of 355 amino acids (aa) with a predicted molecular mass of 41,194 Da was found in the cloned 1583-bp cDNA insert. FsMAPK is highly homologous to SPK1 of fission yeast, FUS3 of budding yeast, MsERK1 of alfalfa, Sur-1 of nematode, and hERK1 of human. That this gene is expressed in F. solani f. sp. pisi was shown by the finding that immunoblot of the fungal extracts with anti-FsMAPK antibodies (Ab) raised in a rabbit against the FsMAPK, expressed in Escherichia coli (E. coli), detected the corresponding protein. DNA blot analysis indicated that Fsmapk is present as a single copy in the fungal genome.

Amino Acid Sequence↗

PubMed1997

Essential role of POU-domain factor Brn-3c in auditory and vestibular hair cell development.

The Brn-3 subfamily of POU-domain transcription factor genes consists of three highly homologous members-Brn-3a, Brn-3b, and Brn-3c-that are expressed in sensory neurons and in a small number of brainstem nuclei. This paper describes the role of Brn-3c in auditory and vestibular system development. In the inner ear, the Brn-3c protein is found only in auditory and vestibular hair cells, and the Brn-3a and Brn-3b proteins are found only in subsets of spiral and vestibular ganglion neurons. Mice carrying a targeted deletion of the Brn-3c gene are deaf and have impaired balance. These defects reflect a complete loss of auditory and vestibular hair cells during the late embryonic and early postnatal period and a secondary loss of spiral and vestibular ganglion neurons. Together with earlier work demonstrating a loss of trigeminal ganglion neurons and retinal ganglion cells in mice carrying targeted disruptions in the Brn-3a and Brn-3b genes, respectively, the Brn-3c phenotype reported here demonstrates that each of the Brn-3 genes plays distinctive roles in the somatosensory, visual, and auditory/vestibular systems.

Animals↗

PubMed1997

Kinetics of eotaxin generation and its relationship to eosinophil accumulation in allergic airways disease: analysis in a guinea pig model in vivo.

Challenge of the airways of sensitized guinea pigs with aerosolized ovalbumin resulted in an early phase of microvascular protein leakage and a delayed phase of eosinophil accumulation in the airway lumen, as measured using bronchoalveolar lavage (BAL). Immunoreactive eotaxin levels rose in airway tissue and BAL fluid to a peak at 6 h falling to low levels by 12 h. Eosinophil numbers in the tissue correlated with eotaxin levels until 6 h but eosinophils persisted until the last measurement time point at 24 h. In contrast, few eosinophils appeared in BAL over the first 12 h, major trafficking through the airway epithelium occurring at 12-24 h when eotaxin levels were low. Constitutive eotaxin was present in BAL fluid. Both constitutive and allergen-induced eosinophil chemoattractant activity in BAL fluid was neutralized by an antibody to eotaxin. Allergen-induced eotaxin appeared to be mainly in airway epithelium and macrophages, as detected by immunostaining. Allergen challenge of the lung resulted in a rapid release of bone marrow eosinophils into the blood. An antibody to IL-5 suppressed bone marrow eosinophil release and lung eosinophilia, without affecting lung eotaxin levels. Thus, IL-5 and eotaxin appear to cooperate in mediating a rapid transfer of eosinophils from the bone marrow to the lung in response to allergen challenge.

Animals↗

PubMed1997

Capillary zone electrophoresis and ion-exchange capillary electrochromatography: analytical tools for probing the Hanford nuclear site environment.

Ion-exchange capillary electrochromatography (IE-CEC) is a relatively new separation technique based on the combination of ion-exchange chromatographic and electrophoretic separation mechanisms. IE-CEC offers both the efficiency of capillary electrophoresis and the selectivity and sample capacity of ion-exchange chromatography. The utility of the method was examined with I- and IO3-, which are common constituents of nuclear wastes at Hanford, Washington and other U.S. Department of Energy (DoE) sites, and ReO4-, a surrogate for TcO4-. The advantages and limitations of IE-CEC relative to capillary zone electrophoresis (CZE) are explored. The chief advantages are increased loading capacity and an alternative selectivity to that of CZE, in addition to increased efficiency (relative to conventional ion-exchange chromatography). The run-to-run reproducibility of IE-CEC, however, was found to be a limitation of the technique.

Chromatography, Ion Exchange↗

PubMed1997

Synthesis of Uniform Ferric Oxide Particles from Deionized Colloids

A modified method was employed to prepare monodispersed colloidal particles of ferric (hydrous) oxide. The method contains three steps: (i) preparation of uniform nuclei of ferric hydrous oxide via a so-called instantaneous nucleation method; (ii) purification of the nuclei suspension via dialysis; (iii) aging of the purified nuclei suspension in a reflux reactor at certain pH. Cubic and pseudocubic alpha-Fe2O3 monodisperse particles which are much smaller than the cubic alpha-Fe2O3 particles obtained from the same reactant through a usual method were produced by aging needle like nuclei at a lower pH. A close-packed three-dimensional QDs (quantum dots) superlattice structure 40 nm in edge length with cubic geometry was formed by self-aggregation between spherical amorphous ferric hydrous oxide nuclei 3-5 nm in diameter. The growth processes of the two kind particles were also illustrated. This study showed an approach to prepare smaller particles from aqueous metal salt solutions in relatively higher concentration, and ordered QDs superlattice structure by controlled self-aggregation of QDs in hydrosol.

Journal Article↗

PubMed1997

Effect of radiation and paclitaxel on p53 expression in murine tumors sensitive or resistant to apoptosis induction.

PURPOSE: Tumors are thought to differ in their response to cytotoxic agents for a variety of reasons including cell cycle kinetics, degree of hypoxia, differential repair, and ability to survive when stressed. Our previous studies showed that murine mammary carcinoma MCA-4 tumors are relatively sensitive to both radiation and paclitaxel and exhibit a significant apoptotic response following treatment in vivo. In contrast, murine squamous cell carcinoma SCC-VII tumors are relatively resistant to radiation and paclitaxel and exhibit relatively little apoptosis following treatment. Since dysfunctional p53 has been shown to be associated with tumor resistance, perhaps through a dysregulated cell loss mechanism, we examined the role of p53 expression in the differential apoptotic response of these two tumors following cytotoxic treatment in vivo. METHODS AND MATERIALS: Mice bearing 8-mm tumors were treated with 40 mg/kg paclitaxel i.v. or 15 Gy local tumor irradiation, and tumors were harvested at several time points up to 2 days following treatment. Histological sections of the tumors were then assessed micromorphometrically for mitotic arrest and apoptosis and immunohistochemically for p53 and p21 expression. RESULTS: In the apoptosis-sensitive MCA-4 tumors, p53 expression increased rapidly following radiation from 13% at baseline to a peak of 45% within 3 h, and expression remained elevated for more than 24 h. Radiation also upregulated p21 suggesting that radiation-induced apoptosis in MCA-4 tumor is p53 dependent. Paclitaxel also induced an increase in both p53 and p21 expression in MCA-4 cells; however, the increase was delayed compared to that after irradiation. This upregulation occurred after the onset of apoptosis which would suggest that paclitaxel-induced apoptosis is p53 independent. Both radiation and paclitaxel caused p53 upregulation in the apoptosis-resistant SCC-VII tumors. The untreated SCC-VII tumor has 25% cells p53 positive and has a very high level of p21 (87% cells positive) which suggests a downstream defect in p53 response. CONCLUSION: These results show that tumor responsiveness to paclitaxel and radiation, measured by tumor growth delay, was associated with apoptotic response. However, although both agents upregulated p53 expression in these tumors, the association between this upregulation and induction of apoptosis was not clear. Additional studies using these and other tumors are warranted to elucidate the role of p53 and its downstream effectors in the in vivo responsiveness of tumors to paclitaxel and radiation.

Animals↗

PubMed1997

Cloning of cutinase transcription factor 1, a transactivating protein containing Cys6Zn2 binuclear cluster DNA-binding motif.

Hydroxy fatty acids from plant cutin were shown previously to induce the expression of the cutinase gene via a palindromic sequence located at -159 base pairs of the cutinase gene in Fusarium solani f. sp. pisi (Nectria hematococca mating type VI). Of the two overlapping palindromes in this sequence, palindrome 2 was found to be essential for the inducibility of cutinase by hydroxy fatty acids. Screening of a phage expression library with the concatenated palindrome 2 as probe detected a distinct cDNA clone encoding a polypeptide designated cutinase transcription factor 1alpha (CTF1alpha) with a calculated molecular weight of 101,109. This protein contains a Cys6Zn2 binuclear cluster motif sharing homology to the Cys6Zn2 binuclear cluster DNA-binding domains of transcription factors from Saccharomyces cerevisiae, S. carlsbergensis, Kluyveromyces lactis, Neurospora crassa, Aspergillus nidulans, and A. flavus. CTF1alpha, expressed in Escherichia coli, showed specific binding to the palindrome 2 DNA fragment but not to palindrome 1 or mutant palindrome 2 DNA fragments, suggesting specific binding of CTF1alpha to palindrome 2. When CTF1alpha was expressed as a fusion protein with the nuclear localization sequence of SV40 in yeast, it transactivated the native cutinase promoter fused to the chloramphenicol acetyl transferase (cat) gene. Mutation of palindrome 2 but not palindrome 1 abolished this transactivation. Thus, CTF1alpha positively acts in vivo by binding selectively to palindrome 2 of the cutinase gene promoter.

Amino Acid Sequence↗

PubMed1997

Evidence for a common sex determination mechanism for pistil abortion in maize and in its wild relative Tripsacum.

Cultivated maize (Zea mays) and several other members of the Tribe Andropogoneae produce unisexual florets. In maize, the formation of two staminate florets in each spikelet on the tassel and a single pistillate floret in each spikelet on the ear includes a pistil abortion process that requires the action of the TASSELSEED2 gene. In Eastern gamagrass (Tripsacum dactyloides) the GYNOMONOECIOUS SEX FORM1 gene appears to perform a similar role in pistil abortion. These genes were shown to be homeologs by restriction fragment length polymorphism mapping and by the failure of the gsf1 and ts2 alleles to complement one another in intergeneric hybrids. Molecular analysis of the gsf1 allele shows that it is caused by a 1.4-kb deletion mutation. Both TASSELSEED2 and GYNOMONOECIOUS SEX FORM1 show similar expression patterns in subepidermal cells of pistils just before abortion. These results suggest that the formation of staminate florets in the Andropogoneae represents a monophyletic trait.

Base Sequence↗

PubMed1997

Effects of chronic administration of tamoxifen and toremifene on DNA adducts in rat liver, kidney, and uterus.

To assess the effects of chronic administration of tamoxifen (TAM) and toremifene (TOR) on genetic damage related to carcinogenesis, we measured DNA adduct formation by (32)P-postlabeling in liver, kidney, and uterus of Fischer rats given TAM or TOR in the diet for 18 months. TAM induced high levels of DNA adducts in the liver in a dose-dependent manner. The total adduct levels were 3000 +/- 870 and 6100 +/- 1500 adducts per 10(9) nucleotides for the 250- and 500-ppm groups, respectively. TOR induced a dose-dependent level of adducts that was lower than that observed for TAM. The total hepatic adduct level was 70 +/- 5, 130 +/- 20, and 70 +/- 20 for 250, 500, and 750 ppm TOR, respectively. Both TAM and TOR induced a low level of adducts in the kidney, and TOR significantly enhanced endogenous DNA adduct formation. The total adduct level was 480 +/- 140, 420 +/- 210, and 680 +/- 80 adducts per 10(9) nucleotides for control, 500 ppm TAM, and 500 ppm TOR, respectively. Although neither TAM nor TOR induced adducts in the uterus, TAM significantly enhanced endogenous DNA modifications in this tissue. The total uterine adduct level was 70 +/- 30, 130 +/- 50, and 70 +/- 20 for control, 500 ppm TAM, and 500 ppm TOR, respectively. These observations demonstrate a correlation between DNA adduct formation and carcinogenicity for these compounds. The effectiveness of TOR and TAM in increasing endogenous DNA adducts indicates that a mechanism other than direct DNA damage may also be involved in their carcinogenicity.

Animals↗

PubMed1997

20-Hydroxyeicosa-tetraenoic acid (20 HETE) activates protein kinase C. Role in regulation of rat renal Na+,K+-ATPase.

It is well documented that the activity of Na+,K+-ATPase can be inhibited by the arachidonic acid metabolite, 20-hydroxyeicosa-tetraenoic acid (20 HETE). Evidence is presented here that this effect is mediated by protein kinase C (PKC). PKC inhibitors abolished 20 HETE inhibition of rat Na+,K+-ATPase in renal tubular cells. 20 HETE caused translocation of PKC alpha from cytoplasm to membrane in COS cells. It also inhibited Na+,K+-ATPase activity in COS cells transfected with rat wild-type renal Na+,K+-ATPase alpha1 subunit, but not in cells transfected with Na+,K+-ATPase alpha1, where the PKC phosphorylation site, serine 23, had been mutated to alanine. PKC-induced phosphorylation of rat renal Na+,K+-ATPase, as well as of histone was strongly enhanced by 20 HETE at the physiologic calcium concentration of 1.3 microM, but not at the calcium concentration of 200 microM. The results indicate that phospholipase A2-arachidonic acid-20 HETE pathway can exert important biological effects via activation of PKC and that this effect may occur in the absence of a rise in intracellular calcium.

Animals↗

PubMed1997

Specific interaction between casein kinase 2 and the nucleolar protein Nopp140.

Casein kinase 2 (CK2) is a multifunctional second messenger-independent protein serine/threonine kinase that phosphorylates many different proteins. To understand the function and regulation of this enzyme, biochemical methods were used to search for CK2-interacting proteins. Using immobilized glutathione S-transferase fusion proteins of CK2, the nucleolar protein Nopp140 was identified as a CK2-associated protein. It was found that Nopp140 binds primarily to the CK2 regulatory subunit, beta. The possible in vivo association of Nopp140 with CK2 was also suggested from a coimmunoprecipitation experiment in which Nopp140 was detected in immunoprecipitates of CK2 prepared from cell extracts. Further studies using an overlay technique with radiolabeled CK2 as a probe revealed a direct CK2-Nopp140 interaction. Using deletion mutants of CK2beta subunits, the binding region of the CK2beta subunit to Nopp140 has been mapped. It was found that the NH2-terminal 20 amino acids of CK2beta are involved. Since Nopp140 has been identified as a nuclear localization sequence-binding protein and has been shown to shuttle between the cytoplasm and the nucleus, the finding of a CK2-Nopp140 interaction could shed light on our understanding of the function and regulation of CK2 and Nopp140.

3T3 Cells↗

PubMed1997

Projections of the dorsomedial nucleus of the intercollicular complex (DM) in relation to respiratory-vocal nuclei in the brainstem of pigeon (Columba livia) and zebra finch (Taeniopygia guttata).

Injections of neuronal tracers were made into the dorsomedial nucleus of the intercollicular complex (DM) of pigeons and zebra finches in order to investigate the projections of this nucleus which has long been implicated in respiratory-vocal control. Despite the fact that pigeons are nonsongbirds and zebra finches are songbirds, the projections were very similar in both species. Most descended throughout the brainstem, taking ventral and dorsal trajectories, which merged in the medulla. Those descending ventrally terminated upon the ventrolateral parabrachial nucleus (PBvl), the nucleus infraolivaris superior, a nucleus of the rostral ventrolateral medulla (RVL), and the nucleus retroambigualis (RAm). Those taking a dorsal trajectory via the occipitomesencephalic tract terminated in the tracheosyringeal part of the hypoglossal nucleus (XIIts), the suprahypoglossal region, and nucleus retroambigualis. There were also substantial projections throughout an arc extending between XIIts and RVL rostrally, and XIIts and RAm caudally. Neurons throughout this arc, which include inspiratory premotor neurons at levels straddling the obex and expiratory premotor neurons more caudally (in RAm), were retrogradely labeled from spinal injections. The DM projections were predominantly ipsilateral, but there were distinct contralateral projections to all the homologous nuclei in both species. All but the projections to PBvl and XIIts were reciprocal. In summary, the projections of DM suggest that it is able to influence all the key motor and premotor nuclei involved in patterned respiratory-vocal activity.

Animals↗

PubMed1997

Demonstration, localization, and development of galanin receptors in the quail oviduct.

We recently isolated an oviposition-inducing peptide that was identified as avian galanin from the oviducts of the Japanese quail. Avian galanin was localized in neural fibers distributed in muscle layers in the uterine and vaginal oviduct regions, and potentiated spontaneous contractions of the uterus and vagina. To elucidate whether an oviposition-inducing effect of avian galanin is due to the direct action on the oviduct, therefore, a specific binding site for avian galanin was determined in the functional quail oviduct in this study. The binding of [125I]iodoavian galanin was primarily located in the oviduct as well as the brain. The galanin binding was specifically inhibited as a function of the concentrations of both avian and rat galanins. The specific binding of avian galanin to the quail oviduct was temperature dependent and reached the maximum level for 1 h at 20 degrees C. In several regions of the oviduct, a higher level of specific galanin binding was observed only in the uterus and vagina. In contrast, the specific binding was low in the isthmus and negligible in the magnum. A similar localization was evident in the functional chicken oviduct. The Scatchard plot analysis of the binding of avian galanin to the uterine preparation revealed that the dissociation constant (Kd) was 0.249 (95% confidence interval, 0.192-0.356) nM, and the number of binding sites was 1.13 (0.99-1.36) fmol per mg tissue, respectively. During development, the galanin-binding sites were apparent in the quail oviduct at 3 weeks of age and the number of binding sites markedly increased between 3 weeks and 3 months of age. However, there was no significant change in the Kd value in the developing quail oviduct. This is the first demonstration of the presence of galanin receptors in the reproductive tract, such as the uterine and vaginal oviduct. The present results suggest that the number of galanin receptors in the oviduct increases during development and that galanin acts directly on the mature uterus and vagina to induce their contractions. This mechanism may be essential to the avian oviposition.

Aging↗

PubMed1997

Multicentric eighth cranial nerve schwannoma.

To our knowledge, only 3 histopathologically proved cases of multicentric eighth cranial nerve schwannoma have been described in the literature since 1981. We describe a patient with 2 isolated eighth cranial nerve schwannomas arising separately from the left cochlea and internal auditory canal. These 2 tumors were diagnosed using magnetic resonance imaging prior to resection, and the diagnosis was further confirmed by intraoperative findings and histopathologic analysis. The genetic molecular basis and clinical features of this rare tumor have been overlooked. The value of the transotic approach for total tumor removal is emphasized.

Adult↗

PubMed1997

Safety of in vivo adenovirus-mediated thymidine kinase treatment of oral cancer.

BACKGROUND: Adenovirus-mediated transfer of the herpes simplex virus thymidine kinase gene (tk) is one of the most effective gene therapy strategies for solid tumors in experimental animal studies. Foundational animal studies in an oral cancer model have demonstrated significant antitumor effects and improved animal survival using this treatment strategy. OBJECTIVE: To assess the safety of adenovirus-mediated transfer of the herpes simplex virus tk gene for the treatment of oral cancer. DESIGN: Oral tumors were established in C3H/HeJ mice and were treated with tk followed by systemic ganciclovir administration. Polymerase chain reaction amplification techniques were used to screen local surrounding tissues and distant organs for the presence of the adenoviral construct. Microscopic examination of the tissues was performed to determine the cytopathic effects of the vector. Blood samples were obtained from the animals to test for liver, renal, and bone marrow function after treatment. RESULTS: The adenoviral vector was present in the livers, lungs, and kidneys of animals treated with the maximal single injection dose of 2 x 10(9) plaque forming units (pfu). No vector was noted systemically after delivery of an equally effective low dose of 1 x 10(8) pfu. Microscopic examination revealed no cytopathic effects in distant organs despite the presence of vector. Results of liver and renal function tests revealed no differences between treated and control animals. There was no statistical difference in white blood cell count, hematocrit, or platelet count between animals treated with ganciclovir and control animals. CONCLUSIONS: Based on these results, the direct delivery of adenovirus-tk followed by ganciclovir administration appears both efficacious and safe in an animal model. However, serum evaluation for adenovirus vector and screening organ function studies should be included in human protocols using this gene therapy scheme.

Adenoviruses, Human↗

PubMed1997

Localization and up-regulation of mucin (MUC2) gene expression in human nasal biopsies of patients with cystic fibrosis.

Using digoxigenin-UTP-labelled human HAM-1 (92 bp) or SMUC41 (850 bp) cRNA probes, the expression and localization of MUC2 gene transcripts were determined by in situ hybridization in human nasal tissues obtained as biopsies from 12 patients with cystic fibrosis (CF): all had been part of a gene therapy trial in which CFTR cDNA-liposome complexes had been delivered by topical application to eight and liposome alone to four as a placebo control. For comparison, there were nasal tissues taken at surgical resection from four non-CF subjects and a further four biopsies taken from normal healthy volunteer controls. Both SMUC41 and HAM-1 probes provided a strong signal. MUC2 mRNA transcripts were present in serous and mucous acini of submucosal glands, ciliated and basal cells of the surface epithelium, and occasional mononuclear inflammatory cells. The percentages (mean +/- SEM) of serous and mucous acini showing positivity for MUC2 gene expression in the four samples surgically resected from non-CF subjects were 25.4 +/- 5.6 and 26.7 +/- 3.3 per cent, respectively. Compared with the non-CF subjects, the mean percentage of acini showing MUC2 gene expression in the four placebo-treated CF subjects was significantly higher for serous (80.5 +/- 12.7 per cent; P < 0.05, t-test), but not for mucous acini (53.1 +/- 16.8 per cent; P = 0.38). In CF and non-CF groups, where present, MUC2 positivity was strongly expressed and constituted approximately 84 per cent of the cell area in serous acini, whereas it was less obvious and was confined to the perinuclear area of cells in mucous acini. A significantly greater proportion of the surface epithelium was positive for MUC2 mRNA transcripts in the CF subjects (89.0, +/- 1.4 per cent) than in the surgically resected tissues of the four non-CF subjects (19.4, +/- 4.0 per cent) (P = 0.02). In the eight CFTR-cDNA-treated subjects, there was an overall trend to reduction, but no statistically significant alteration of MUC2 gene expression. It is concluded that the MUC2 gene is expressed at three- to four-fold higher levels in CF nasal mucosa than in non-CF nasal tissue and that it is expressed in a variety of cells additional to submucosal mucus-secreting glands.

Adult↗