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W Poller

Publications and source records attributed to W Poller.

53 records · Page 3Linked to original sources
PubMed1992

Cloning of the human alpha 2-macroglobulin gene and detection of mutations in two functional domains: the bait region and the thiolester site.

Overlapping genomic clones of the human alpha 2-macroglobulin (alpha 2M) gene were isolated from a cosmid library and were used to map 80 kb of the chromosomal region of this gene. Fragments carrying the two exons encoding the bait region and the exon encoding the thiolester site were partially sequenced and PCR primers were designed for the amplification of both functional domains. By direct genomic sequencing of these domains in 30 healthy individuals and in 30 patients with chronic lung disease three mutations were detected. The first was a sequence polymorphism occurring near the thiolester site of the gene, changing Val1000 (GTC) to Ile1000 (ATC), with allele frequencies of 0.30 (GTC) and 0.70 (ATC), respectively. No difference of alpha 2M serum levels was observed for these two alleles. The second mutation occurred within the thiolester site of one patient, changing Cys972(TGT) to Tyr972(TAT). Since activation of the internal thiolester formed between Cys972 and Gln975 in each of the subunits of the tetrameric alpha 2M is involved in the covalent cross-linking of the activating proteinase, this mutation is predicted to interfere with alpha 2M function. The alpha 2M serum level was within the normal range in this patient. In one healthy individual we detected an alteration of the bait region sequence, which is usually encoded by two different exons separated by an intron of size 1.6 kb. In this individual, PCR amplification of genomic DNA using the bait region primers produced the common fragment of size 1.8 kb and an additional variant fragment of size 0.23 kb. This finding, and the genomic sequencing data of this individual, indicate that he carries two different alleles of the alpha 2M gene: one with the regular structure (bait exon I-intron-bait exon II), the other with the two bait exons fused into one. Direct genomic sequencing of the two alpha 2M functional domains is a useful tool for the detection of the genetic, and possibly the functional, heterogeneity of alpha 2M. This, in turn, may provide some insight into the hitherto unknown physiological role(s) of alpha 2M, by studying in vivo effects of naturally occurring mutations of the gene.

Base Sequence↗
PubMed1991

Sequence analysis of the cystic fibrosis gene in patients with disseminated bronchiectatic lung disease. Application in the identification of a cystic fibrosis patient with atypical clinical course.

The diagnosis of classical cystic fibrosis (CF) is easily made by clinical assessment alone, but may be missed or delayed in cases with an atypical clinical course. In a recent major study the age at diagnosis varied between 2 months and 47 years. For diagnostic purposes we have investigated the cystic fibrosis transmembrane regulator (CFTR) gene in 10 adult patients (age 18 to 45 years) with chronic obstructive pulmonary disease since childhood or adolescence and bronchiectases disseminated through both lungs. Only one subject (a 29-year-old male) had exocrine pancreatic insufficiency (PI); all others were pancreatic-sufficient (PS). The first nucleotide (ATP)-binding fold of the CFTR was analyzed by direct sequencing of polymerase chain reaction (PCR)-amplified genomic DNA in these cases. Two patients with different phenotypes (one PI, one PS) were found to be homozygous for the common delta F508 mutation of the CFTR gene, which proved the diagnosis of cystic fibrosis in their cases and allowed genetic counselling. The PS patient had normal sweat tests and had not previously been recognized as having CF. Four other patients were heterozygous for delta F508, with no other mutation in exons 10 or 11 of the gene, and four patients had normal sequences of these exons. Because only about 70% of all CF chromosomes carry delta F508, the unexpectedly high frequency (4/8 = 50%) of heterozygosity for delta F508 among the non-delta F508/delta F508 patients with bronchiectases suggests that some of these might also have unrecognized CF with rare genotypes and mutations in any of the 22 exons not sequenced.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1991

DNA polymorphisms associated with a new alpha 1-antitrypsin PIQ0 variant (PIQ0riedenburg).

A new PIQ0 variant (PIQ0riedenburg) is described; it is caused by a complete deletion of the alpha 1-antitrypsin (alpha 1 AT) gene. The deletion gives rise to four new restriction fragment length polymorphisms (RFLPs) detected with a genomic probe of the 5' region of the gene. Analysis of the RFLPs indicates that the deletion starts immediately upstream of exon Ic. The deletion extends into the 3' flanking region of the gene but does not include the alpha 1 AT-related gene (the PIL gene), which is located 12 kb downstream of the alpha 1 AT gene.

Alleles↗
PubMed1990

Highly variable clinical course in severe alpha 1-antitrypsin deficiency--use of polymerase chain reaction for the detection of rare deficiency alleles.

Among 20 individuals with severe alpha 1-antitrypsin (alpha 1AT) deficiency we observed extremely variable clinical phenotypes ranging from rapidly progressive lung disease fatal at the age of 42 years to an asymptomatic individual with normal lung function at the age of 50 years. Eighteen subjects, including the asymptomatic one, carried the deficient Pi ZZ phenotype as determined by isoelectric focusing (IEF). Their mean alpha 1AT serum level was 36.7 +/- 7.7 mg/dl. DNA restriction analysis showed that all of them had the classical Pi Z-allele-associated DNA haplotype, thus confirming the IEF data. Obviously not all Pi ZZ individuals will have clinical sequelae caused by this genotype. The important differences in clinical course observed could not be explained by smoking habits alone. Probably additional factors are pertinent to the pathogenesis of the lung disease associated with alpha 1AT deficiency (defects in other genes, environmental influences other than smoking). In two patients with very low alpha 1AT serum levels definitive phenotyping by IEF was not possible. Therefore we investigated the molecular basis of their deficiency using polymerase chain reaction (PCR) amplification of the coding exons of their alpha 1AT genes and direct sequencing of the amplification products. Sequence data analysis showed that one of these patients, who had initially been phenotyped as Pi ZZ by IEF, had in fact the genotype Pi QObellinghamZ, thus explaining her low alpha 1AT serum level of 20 mg/dl. The other patient (alpha 1AT serum level 3.7 mg/dl) exhibited the rare genotype Pi MheerlenQOgranite falls. Despite his nearly complete alpha 1AT deficiency, he suffered from only moderately severe pulmonary disease at the age of 42 years.

Adult↗
PubMed1990

DNA polymorphisms of the alpha 1-antitrypsin gene region in patients with chronic obstructive pulmonary disease.

Alpha 1-antitrypsin (AAT) is an important part of the defence mechanism of the lung against proteolytic attack. The Z and Null mutants of the AAT gene are associated with very low or missing serum concentrations of AAT, so that for individuals with genotypes ZZ or Null there is a very high risk of developing chronic obstructive pulmonary disease (COPD). In more than 90% of the patients suffering from COPD, however, the common MM phenotype of AAT is expressed at normal AAT serum levels. The MM phenotype has a heterogeneous constitution and the alleles M1, M2 and M3 are distinguished by isoelectric focusing. At the DNA level many mutants of the AAT gene may exist that cannot be recognized by IEF. In this paper we report DNA sequence heterogeneity of the AAT gene region among 137 patients with COPD and 130 healthy control subjects. All 267 individuals studied were MM phenotype. Several restriction fragment length polymorphisms (RFLPs) were observed using genomic probes of the AAT gene. One allele (T2) of a Taq I RFLP located 1 kb downstream of the AAT gene was significantly more frequent in patients (15.3%) than in controls (5.4%) (P less than 0.005). The relative incidence of COPD was 3.3 times higher for subjects carrying at least one T2 allele than for the common T1T1 genotype. The T2 allele may be in linkage disequilibrium with a functionally deficient variant of AAT or some gene in close neighbourhood, e.g. the alpha 1-antichymotrypsin gene. A deletion of 1.8 kb in the alpha 1-antichymotrypsin-like gene (PIL gene) occurs at a frequency of 0.26 in patients and in control subjects as well.

Alleles↗
PubMed1990

[Pulmonary gas exchange in conventional ventilation and high frequency ventilation in severe respiratory insufficiency].

During high frequency jet ventilation (HFJV) adequate alveolar ventilation may be achieved with lower (-35%, p less than 0.0005) central airway pressures than during conventional mechanical ventilation (CMV). Due to increasing ventilation-perfusion inequalities, however, intrapulmonary shunt is then considerably increased (+52%, p less than 0.0005). In disease states with extensive shunting (e.g. ARDS) both ventilation modes can provide sufficient oxygenation only if high PEEP is applied.

High-Frequency Jet Ventilation↗
PubMed1989

[Mucoviscidosis: late diagnosis despite typical clinical features].

An 18-year-old girl was hospitalized because of a treatment-refractory broncho-pneumonia requiring artificial ventilation. She had been suffering from recurrent respiratory infection since the age of three years. Chest X-ray films demonstrated bronchiectasis: Pseudomonas, Klebsiella and Candida albicans were isolated from the respiratory tract. The correct diagnosis of the underlying disease had not previously been made. A sweat test, when aged 15 years, was borderline abnormal. Despite the application of all available therapeutic measures she died in cardiorespiratory failure from an overwhelming pulmonary infection. The typical clinical features and the findings at autopsy established the diagnosis of mucoviscidosis.

Adolescent↗
PubMed1989

Detection of an alteration of the alpha 2-macroglobulin gene in a patient with chronic lung disease and serum alpha 2-macroglobulin deficiency.

alpha 2-Macroglobulin (A2M) is a major human plasma protease inhibitor capable of inhibiting most endopeptidases tested so far. In the case of the other major plasma protease inhibitor, alpha 1-antitrypsin, genetically determined deficiency states are known to increase the risk of chronic obstructive pulmonary disease (COPD) 20- to 30-fold in affected individuals. No defects of the A2M gene have been described as yet, but A2M may play a role in the regulation of protease activity in the lung, especially with respect to those proteases not inhibited by alpha 1-antitrypsin. We report here the molecular genetic detection of an alteration of the A2M gene in a patient with serum A2M deficiency and chronic lung disease since childhood. The alteration involves restriction sites detected with 10 different enzymes and is most probably caused by a major deletion or rearrangement of the gene. Nine of the restriction enzymes used detected no polymorphisms in 40 healthy control subjects and 39 COPD patients. The polymorphism detected in this patient with the enzyme PvuII was different from another described previously, and was found in this patient only. The patient is heterozygous for an alteration in the A2M gene; this may be responsible for his serum A2M deficiency and may be relevant to the early onset of pulmonary disease in his case.

Adult↗
PubMed1981

Study of the sensitivity and specificity of computerized tomography in the detection of calcified gallstones which appears radiolucent by conventional roentgenography.

Radiolucent gallstones frequently contain significant calcium deposits. Their detection is important in the evaluation of patients for medical gallstone dissolution treatment. The sensitivity and specificity of computerized tomography (CT) in detecting calcium was studied in 20 patients with radiolucent and in 3 with radiopaque gallstones. Although the sensitivity of the CT scan was somewhat higher than that of conventional radiography -- 46% versus 23%, respectively, for a calcium content of at least 4% -- the CT scan was negative in 4 out of 6 patients in whom the percentage of calcium in the gallstones ranged between 10 and 100. The CT scan was specific: there were no false positive results. The results of the CT scan were not related to the amount or type of calcium salt present. The study shows that the presently used CT scan of the gallbladder is not sensitive enough to select gallstone patients for medical dissolution treatment.

Adult↗
PubMedDate not supplied

Improved phenotyping of alpha 1-antichymotrypsin (ACT) by isoelectric focusing and immunoprinting: first demonstration of a deficient protein variant in the ACT system.

Genetic variation of human alpha 1-antichymotrypsin (ACT) was investigated in sera using thin-layer polyacrylamide gel isoelectric focusing (pH range 4.0-6.5) followed by immunoprinting with a monospecific anti-human ACT antibody. Sialidase-treated samples showed a microheterogeneous banding pattern which consisted of two major and several additional minor components with isoelectric points between pH 5.0 and 5.3. A population study of 200 unrelated individuals from southern Germany revealed no genetic variation. In a clinical investigation, however, we found a unique banding pattern in a female patient suffering from chronic obstructive pulmonary disease. In comparison with the monomorphic normal type the detected variant phenotype shows two additional bands that have lower intensities and are located cathodically to their major bands. Inheritance of the deficient IEF variant "ACT Bochum" was confirmed by a family study. To our knowledge this is the first genetic ACT mutant to be observed at the protein level.

Female↗