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Biomedical subjects

M C Iannuzzi

Publications and source records attributed to M C Iannuzzi.

At least 37 records · Page 2Linked to original sources
PubMed1995

Cytokines in the bronchoalveolar lavage fluid of patients with active pulmonary sarcoidosis.

Numerous cytokines are thought to be important in the pathogenesis of granulomatous inflammation and subsequent fibrosis in sarcoidosis. Interleukin (IL)-6 and IL-8, two recently described cytokines with a broad spectrum of proinflammatory effects, could participate in this disease. We obtained bronchoalveolar lavage fluid (BALF) from 16 subjects (13 African-American, three Caucasian) with untreated active pulmonary sarcoidosis and 10 healthy nonsmoking volunteers (nine Caucasian, one African-American). Concentrated BALF was analyzed by an ELISA for IL-6, IL-8, and albumin. The median IL-6 level was 9.8 pg/mg albumin (range, 0-278) for the sarcoid group compared with 0.14 pg/mg (range, 0.14-9.8) in the control subjects (p = 0.001). The corresponding values for IL-8 were 202 pg/mg (range, 35-2179) versus 5.0 pg/mg (range, 0-44) in the control subjects (p < 0.001). Among the sarcoid patients, BALF IL-6 and IL-8 levels correlated with each other (r = 0.96, p < 0.001), and both cytokines correlated with the BALF neutrophil percentage (r = 0.96 and 0.95, respectively; p < 0.001 for both). No difference was detected in IL-8 concentrations as measured by ELISA in culture supernatants of alveolar macrophages obtained from five sarcoid patients and five control subjects. We conclude that IL-6 and IL-8 are elevated in BALF of patients with active sarcoidosis and may be important modulators of the disease process.

Adult↗
PubMed1994

Cystic fibrosis-related diabetes is associated with HLA DQB1 alleles encoding Asp-57- molecules.

The incidence of insulin-dependent diabetes in individuals with cystic fibrosis is nearly 100 times greater than in the general population. In the latter group, strong associations with specific HLA DQA1 and DQB1 alleles have been observed. To determine if a similar distribution of alleles occurs in cystic fibrosis patients with diabetes, a cohort of these individuals was typed for DQA1 and DQB1 alleles. HLA DQB1*0201 (Asp57-) was more frequent in diabetics compared to controls (40.4 vs 28%), while the frequency of alleles encoding Asp57+ molecules was lower in diabetics relative to both the cystic fibrosis-only controls (P = 0.025) and the general population (P = 0.008). The presence of at least one protective DQA1-DQB1 heterodimer (i.e., Arg52- and Asp57+, respectively) in cis or trans was significantly lower in the diabetics than in either of the control groups. Thus, the HLA alleles known to be associated with insulin-dependent diabetes mellitus in the general population are also found in diabetics with cystic fibrosis.

Adolescent↗
PubMed1992

Characterization of an intron 12 splice donor mutation in the cystic fibrosis transmembrane conductance regulator (CFTR) gene.

Cystic fibrosis, the most common lethal genetic disease in the white population, is caused by mutations in the cystic fibrosis transmembrane conductance regulator (CFTR) gene. Analysis of DNA from a pancreatic insufficient patient by chemical mismatch cleavage and subsequent DNA sequencing led to the identification of a potential splice mutation in the CFTR gene. A transition of the invariant guanosine to adenosine (1898 + 1G > A) was found at the splice donor site of intron 12. To determine the effect of this mutation on the patient's CFTR transcripts, RNA from the nasal epithelium was reverse transcribed and amplified by the polymerase chain reaction (RT-PCR). Direct sequencing of the PCR products revealed that the transcript from the chromosome with the 1898 + 1G > A mutation had skipped exon 12 entirely, resulting in a joining of exons 11 and 13. Deletion of exon 12 results in the removal of a highly conserved region which encodes the Walker B consensus sequence of the first nucleotide-binding fold of CFTR.

Adult↗
PubMed1991

Analysis of the relationship of von Willebrand disease (vWD) and hereditary hemorrhagic telangiectasia and identification of a potential type IIA vWD mutation (IIe865 to Thr).

Reports of families with members affected with both von Willebrand disease (vWD) and hereditary hemorrhagic telangiectasia (HHT) suggest a possible relationship between these two disorders. vWD, the most common inherited bleeding disorder in humans, is due to either a quantitative or qualitative defect in von Willebrand factor (vWF). The gene for vWF has been cloned and mapped to chromosome 12 (12p12----12pter). HHT, an uncommon inherited bleeding disorder, is characterized by malformed, dilated, fragile blood vessels. The chromosomal location of the gene for HHT is unknown. We studied two families by RFLP analysis to determine whether there is a molecular basis for the association of vWD and HHT. Family A is affected with both type IIA vWD and HHT; family B is affected with HHT alone. Linkage of HHT to the vWF gene was not detected, and vWF was ruled out as a candidate gene for HHT. The vWF gene was found to be tightly linked to type IIA vWD in family A (lod score 3.61 at recombination fraction .00). By PCR and DNA sequence analysis of vWF exon 28, a single T----C transition resulting in the substitution of Thr for Ile865 was identified. This substitution is located immediately adjacent to two previously identified type IIA vWD mutations.

Alleles↗
PubMed1991

Two frameshift mutations in the cystic fibrosis gene.

Cystic fibrosis (CF) is a recessive disease caused by mutations in the CF transmembrane conductance regulator (CFTR) gene. We have identified in exon 7 two frameshift mutations, one caused by a two-nucleotide insertion and the other caused by a one-nucleotide deletion; these mutations--CF1154insTC and CF1213delT, respectively, are predicted to shift the reading frame of the protein and to introduce UAA(ochre) termination codons at residues 369 and 368.

Adolescent↗
PubMed1990

Approaches to localizing disease genes as applied to cystic fibrosis.

Using chromosome jumping and walking and restriction fragment length polymorphism (RFLP) analysis, we have defined the region which must contain the cystic fibrosis gene. DNA segments spanning approximately 250 kb in the direction of the gene were isolated and used to identify several new polymorphisms informative in cystic fibrosis families. These RFLPs include a highly polymorphic, CA/GT repeat, and a 10 bp insertion uncovered using the polymerase chain reaction. By analyzing a family with a recombination near the gene, we can exclude this region as containing the mutation. Data on the extent of linkage disequilibrium of these markers provides additional information on where the gene is located.

Base Sequence↗
PubMed1990

A cystic fibrosis pancreatic adenocarcinoma cell line.

We established a pancreatic adenocarcinoma cell line (CFPAC-1) from a patient with cystic fibrosis (CF) and assessed some of its properties. The cells show epithelial morphology and express cytokeratin and oncofetal antigens characteristic of pancreatic duct cells. Basal and stimulated levels of cAMP and cAMP-dependent protein kinase and the biophysical properties of single Cl- channels in CFPAC-1 are similar to those of airway and sweat gland primary cultures and Cl(-)-secreting epithelial cell lines. Anion transport and single Cl- channel activity was stimulated by Ca2+ ionophores but not by forskolin, cAMP analogs, or phosphodiesterase inhibitors. The cells express the CF gene and manifest the most common CF mutation, deletion of three nucleotides resulting in a phenylalanine-508 deletion. These properties have been stable through greater than 80 passages (24 months), suggesting that CFPAC-1 can serve as a continuous cell line that displays the CF defect.

Adenocarcinoma↗
PubMed1990

Expression of normal and cystic fibrosis phenotypes by continuous airway epithelial cell lines.

Continuous epithelial cell lines from individuals with cystic fibrosis (CF) and normal controls are required to understand the genetic and cellular defects in CF. We used retroviruses to transduce SV40 large T antigen into nasal epithelial cells. Transformed continuous cell lines were isolated that expressed epithelial markers, cytokeratin, and tight junctions. Northern blot analysis shows that all of the cell lines express the putative CF gene mRNA. Studies of transepithelial electrolyte transport show that CF and normal cell lines develop a transepithelial electrical resistance. Normal but not CF cell lines secreted Cl- in response to agonists that increase cellular levels of adenosine 3',5'-cyclic monophosphate (cAMP) (isoproterenol, forskolin, and a membrane-permeant analogue of cAMP) or in response to a tumor-promoting phorbol ester that activates protein kinase C. In contrast, the Ca2(+)-elevating agonist bradykinin and the Ca2+ ionophore A23187 stimulated secretion in both normal and CF cell lines. The continuous cell lines we have produced maintain their proper phenotypes and will serve as useful tools in understanding the pathophysiology of CF.

Antigens, Polyomavirus Transforming↗
PubMed1990

Reverse genetics and cystic fibrosis.

The protein responsible for cystic fibrosis has been identified using an approach called "reverse" genetics. This approach relies on the chromosomal map position to direct the search for a disease gene, several novel cloning strategies to isolate the gene, and the gene's sequence to define the abnormal protein. Reverse genetics, because it does not require prior knowledge of the protein's biochemical function, has wide utility and is being used to define the defects in many single-gene disorders. This update presents the reverse genetics approach and uses cystic fibrosis to illustrate the principles involved.

Chromosome Mapping↗
PubMed1989

Identification of the cystic fibrosis gene: chromosome walking and jumping.

An understanding of the basic defect in the inherited disorder cystic fibrosis requires cloning of the cystic fibrosis gene and definition of its protein product. In the absence of direct functional information, chromosomal map position is a guide for locating the gene. Chromosome walking and jumping and complementary DNA hybridization were used to isolate DNA sequences, encompassing more than 500,000 base pairs, from the cystic fibrosis region on the long arm of human chromosome 7. Several transcribed sequences and conserved segments were identified in this cloned region. One of these corresponds to the cystic fibrosis gene and spans approximately 250,000 base pairs of genomic DNA.

Animals↗
PubMed1989

Isolation of additional polymorphic clones from the cystic fibrosis region, using chromosome jumping from D7S8.

The cystic fibrosis (CF) locus has been located, by both linkage analysis and physical mapping, to a 900-kb region of 7q22-31 flanked by D7S8 (J3.11) and D7S23 (XV-2c). Using a 100-kb general jumping library, we isolated two sequential jump clones, J31 and J29, to one side of the D7S8 region and one jump clone, J32, to the other side of D7S8, so that the total region covered is about 300 kb. Three new RFLPs were detected by J29 and J32. Using PFGE mapping and the three jump clones, we found it possible to orient D7S8 on the chromosome and, by linkage analysis, to further narrow the CF region by 100 kb. The orientation of D7S8 will be useful for directing the isolation of other jump clones toward the CF locus. Though the newly described RFLPs are in considerable linkage disequilibrium with D7S8 polymorphisms, they increase the informativeness of genetic markers in the D7S8 region and should be useful in prenatal diagnosis.

Chromosomes, Human, Pair 7↗
PubMed1988

Physical mapping of the cystic fibrosis region by pulsed-field gel electrophoresis.

The gene for cystic fibrosis (CF) is known to be flanked by the closely linked DNA markers met and J3.11 on chromosome 7. Using the technique of pulsed-field gel electrophoresis, we have constructed a complete overlapping restriction map of approximately 3000 kb of DNA in this region. The met and J3.11 probes are found to be between 1300 and 1800 kb apart, which compares well with their genetic distance of 1-2 cM. The CF gene must be located within this interval, and the availability of this physical map should be of considerable utility in mapping additional clones as the search for the gene proceeds.

Cell Line↗
PubMed1988

The introduction of biologically active foreign genes into human respiratory epithelial cells using electroporation.

A simple method for introducing genes into respiratory epithelial cells would assist molecular studies of a variety of pulmonary disorders. Several different techniques for introducing foreign DNA into cells have been described but have either not been useful for respiratory epithelial cells or are difficult and cumbersome to perform. Electroporation is a simple technique that consists of exposing a cell-DNA suspension to an electric shock. Although it has been used to introduce genes into a variety of cell types, it has not previously been applied to respiratory epithelial cells. Human nasal epithelial cells were transfected with the plasmid pRSVCAT, which is an expression vector containing the origin of replication of pBR322 coupled to the Rous sarcoma virus (RSV) long terminal repeat (LTR) region driving the coding sequence for the chloramphenicol acetyltransferase (CAT) gene. The CAT gene is useful for determining optimal conditions for electroporation since it is not normally present in eukaryotic cells, and CAT activity correlates with the level of CAT mRNA; this provides a measure of expression of introduced foreign genes. Successful expression of the CAT gene was demonstrated by electroporation, whereas calcium phosphate transfection resulted in very low CAT activity. Optimal conditions for electroporation of respiratory epithelial cells were determined. Electroporating nasal epithelial cells using 500 volts, a DNA concentration of 10 micrograms/ml, and a sucrose buffer yielded the highest CAT activity, which peaked at 48 h after electroporation.

Avian Sarcoma Viruses↗
PubMed1987

Construction of a general human chromosome jumping library, with application to cystic fibrosis.

In many genetic disorders, the responsible gene and its protein product are unknown. The technique known as "reverse genetics," in which chromosomal map positions and genetically linked DNA markers are used to identify and clone such genes, is complicated by the fact that the molecular distances from the closest DNA markers to the gene itself are often too large to traverse by standard cloning techniques. To address this situation, a general human chromosome jumping library was constructed that allows the cloning of DNA sequences approximately 100 kilobases away from any starting point in genomic DNA. As an illustration of its usefulness, this library was searched for a jumping clone, starting at the met oncogene, which is a marker tightly linked to the cystic fibrosis gene that is located on human chromosome 7. Mapping of the new genomic fragment by pulsed field gel electrophoresis confirmed that it resides on chromosome 7 within 240 kilobases downstream of the met gene. The use of chromosome jumping should now be applicable to any genetic locus for which a closely linked DNA marker is available.

Bacteriophage lambda↗
PubMed1987

The deletion in both common types of hereditary persistence of fetal hemoglobin is approximately 105 kilobases.

The most common forms of hereditary persistence of fetal hemoglobin (HPFH) involve large deletions that remove the adult delta and beta genes but leave the paired fetal genes (G gamma and A gamma) intact. The size of these deletions has previously eluded exact definition. Using pulsed-field gel electrophoresis and the enzyme SfiI, which cuts only rarely in genomic DNA, we have constructed a large-scale restriction map of the beta-globin cluster in normal and HPFH DNA. The deletions in HPFH-1, which occurs in American blacks, and in HPFH-2, which occurs in Ghanaian blacks, are found to be approximately 105 kilobases (kb) in length, though the endpoints are staggered by approximately 5 kb. The fact that two previously reported gamma delta beta-thalassemia deletions to the 5' side of the beta-globin cluster are also about 100 kb suggests a common mechanism, possibly involving the loss of a complete chromatin loop.

Chromatin↗