A method for the rapid construction of cRNA standard curves in quantitative real-time reverse transcription polymerase chain reaction.

Quantification of nucleic acids, especially of mRNA, is increasingly important in biomedical research. The recently developed quantitative real-time polymerase chain reaction (PCR) - a highly sensitive technology for the rapid, accurate and reproducible quantification of gene expression - offers major advantages over conventional quantitative PCR. Transcript quantification is performed in the exponential phase of the PCR reaction through extrapolation of fluorescence signals from a standard calibration curve which represents the initial copy number for a given fluorescence signal. We have developed a method for gene transcript quantification which is based on a LightCycler - assisted real-time PCR in combination with a simple and rapid approach for the construction of external cRNA standards with identical gene sequences as the target gene. Synthesis of cRNAs was performed by in vitro transcription with T7 RNA polymerase followed by reverse transcription and real-time PCR. We applied this approach for transcript quantification of eukaryotic initiation factor 3 p110 (EIF3S8) mRNA in normal testicular tissue. We also present a rapid and simple strategy for the construction of cRNA standards for use in real-time PCR.

Real-time PCR analysis of the N-acetyltransferase NAT1 allele *3, *4, *10, *11, *14 and *17 polymorphism in squamous cell cancer of head and neck.

Although tobacco smoke has been established as a main risk factor in the development of head and neck squamous cell cancer (HNSCC), genetic polymorphisms of xenobiotic metabolizing enzymes are supposed to modulate an individual's susceptibility to smoking-related HNSCC. N-acetyltransferase (NAT) 1 gene is known to be polymorphic and its protein product is implicated in the activation and detoxification of carcinogens, such as aromatic amines, present in tobacco smoke. We developed a rapid and reproducible LightCycler-assisted real-time polymerase chain reaction (PCR) for NAT1 genotyping, which allowed the parallel differentiation of NAT1*3, *4, *10 and *11 alleles and separately of NAT1*14 and *17 alleles within 60 min without the need for further post-PCR processing. In order to investigate the role of the NAT1 gene polymorphism as a risk-modifying factor in HNSCC, we tested for the presence of NAT1*3, *4, *10, *11, *14 and *17 alleles in a case-control study of 291 HNSCC patients and 300 healthy controls of Caucasian origin. Our findings suggest that in Caucasians, the risk of HNSCC is not associated with NAT1 polymorphism. The overall distribution of NAT1 allele frequencies was not significantly different among cases and controls. The presence of the fast acetylator NAT1*10 and NAT1*11 alleles did not significantly increase the risk of HNSCC and no modifying effect of NAT1*10 was observed among smokers. This new approach in NAT1 genotyping substantially increases throughput of sample analysis and, therefore, enhances opportunities to study NAT1 as a risk factor in different cancers in large-scale studies.

[Chronic progressive polycythemia and thrombocytosis]. / Chronisch progrediente Polyglobulie und Thrombozytose.

The 73-year-old female patient presented with chronic progressive erythrocytosis diagnosed 5 years ago which now is accompanied by thrombocytosis. She complains about generalised itching, pain in distal limbs and shows marked plethora. Having excluded major causes of secondary erythrocytosis the diagnosis was polycythaemia vera with a typical constellation of symptoms, findings and course of disease. Under treatment with 5-Hydroxyurea and repeated phlebotomy thrombocyte count and haematocrit normalised and the patient recovered her usual vitality. Limb pain, itching and plethora disappeared.

The effect of C1-esterase inhibitor in definite and suspected streptococcal toxic shock syndrome. Report of seven patients.

OBJECTIVE: To evaluate the effect of adjunctive C1-esterase inhibitor substitution therapy on clinical characteristics and outcome of patients with streptococcal toxic shock syndrome (TSS). DESIGN: Observational. SETTING: Medizinische Poliklinik, University of Bonn, Germany. PATIENTS: Seven patients with direct or indirect evidence of streptococcal TSS. INTERVENTION: In addition to conventional and supportive therapy, all patients received 2-3 single doses of C1-esterase inhibitor totaling 6,000-10,000 U within the first 24 h after admission. MEASUREMENTS AND RESULTS: All patients developed fulminant septic shock, multiorgan failure and/or capillary leak syndrome and necrotizing fasciitis within 10-72 h following the onset of first symptoms. Between 1 and 4 days following administration of C1-esterase inhibitor, a marked shift of fluid from extravascular to intravascular compartments took place in all but one patient, accompanied by a transient intra-alveolar lung edema and rapidly decreasing need for adrenergic agents. Six of seven patients survived. CONCLUSIONS: These clinical observations in a small series of patients and the favorable outcome point towards a positive effect of early and high-dose administration of C1-esterase inhibitor as adjunctive therapy in streptococcal TSS. The possible mechanism involved may be the attenuation of capillary leak syndrome (CLS) via early inactivation of complement and contact systems. Controlled studies are needed to establish an improvement of the survival rates of patients with streptococcal TSS following administration of C1-esterase inhibitor.

High percentage of false-positive results of cytokeratin 19 RT-PCR in blood: a model for the analysis of illegitimate gene expression.

Cytokeratin 19 (CK19) RT-PCR is widely used in order to detect circulating tumor cells in peripheral blood and bone marrow. However, increasing amounts of information support the fact that it is also associated with a high percentage of false-positive results. In our study, we not only managed to demonstrate the significant limitations of this method, but were also able to clarify the reasons behind these limitations. We developed a completely novel RT-PCR for CK19 and sequenced an intron at nucleotide (nt) 980 of the CK19 mRNA to exclude DNA contamination. Tumor dilution experiments were performed in order to analyze the specificity and sensitivity of the method. Control experiments using the blood of healthy donors were performed. Tumor cell dilution experiments gave a detection limit of one tumor cell. If tumor cells were mixed with an equal volume of pure mononuclear cells, the detection limit was 1 tumor cell in 10(5) mononuclear cells. RT-PCR of mononuclear cells from healthy blood donors gave false-positive results in 29% of the cases. We conclude that a significant decrease in the sensitivity of CK19 RT-PCR occurs if it is performed in blood cells and that the illegitimate CK19 gene expression in normal cells can lead to false-positive results. These limitations have to be taken into account if RT-PCR is to be used for the detection of tumor cells either in blood or in bone marrow in clinical practice.

Identification of syntenin and other TNF-inducible genes in human umbilical arterial endothelial cells by suppression subtractive hybridization.

Endothelial cells play an important regulatory role in inflammatory responses by upregulating various proinflammatory gene products including cytokines and adhesion molecules. A highly potent mediator of this process is tumor necrosis factor-alpha (TNF). In the present study, the suppression subtractive hybridization (SSH) method was employed to identify rarely transcribed TNF-inducible genes in human umbilical arterial endothelial cells. Following mRNA isolation of non-stimulated and TNF-stimulated cells, cDNAs of both populations were prepared and subtracted by suppression PCR. Sequencing of the enriched cDNAs identified 12 genes differentially expressed including vascular cell adhesion molecule-1, monocyte chemoattractant protein-1, interleukin-8 and IkappaBalpha, an inhibitor of the transcription factor nuclear factor-kappaB. Interestingly, also syntenin, a PDZ motif-containing protein which binds to the cytoplasmic domain of syndecans, was identified by SSH. Time course studies using RT-PCR analysis confirmed that all genes were differentially expressed and rapidly induced by TNF. Our data reveal that SSH is a powerful technique of high sensitivity for the detection of differential gene expression in primary arterial endothelial cells.

Cholesterol enhances contractile responses in isolated small mesenteric arteries of normotensive and spontaneously hypertensive rats.

OBJECTIVE: In order to examine possible mechanisms by which hypercholesterolemia may contribute to the development of cardiovascular disease, we investigated the effect of cholesterol enrichment on contractility in isolated small rat mesenteric arteries. DESIGN: Contractile responses of cholesterol-enriched isolated small mesenteric arteries of normotensive Wistar-Kyoto (WKY) rats and spontaneously hypertensive rats (SHR) were compared with control groups. METHODS: First- to second-order mesenteric arteries (327-349 microm internal lumen diameter) were dissected from the mesenteric bed of 10-20-week-old male WKY rats and SHR, and incubated in cholesterol-free and cholesterol-rich (150 microg/ml) medium. Isolated arteries were mounted on a Mulvany-Halpern myograph for measurement of isometric tension. RESULTS: Cholesterol significantly increased active wall tension and active wall pressure in WKY rat arteries and active wall tension in SHR arteries in response to potassium chloride, norepinephrine and serotonin (P < 0.05). In addition, contractile responses to all agonists were significantly higher in cholesterol-enriched SHR arteries compared with cholesterol-enriched WKY rat vessels (P < 0.05). CONCLUSIONS: These findings suggest that elevated cholesterol content enhances agonist-stimulated contractility in small mesenteric resistance arteries, providing a possible mechanism by which hypercholesterolemia may contribute to the development of hypertension.

[Severe soft tissue infection with bulla formation, sepsis, multiple organ failure]. / Schwere Weichteilinfektion mit Blasenbildung, Sepsis, Multiorganversagen.

A 53-year old patient with diabetes mellitus presented with a painful swelling of the left thigh in an out-of-town hospital. Because of the slow progression associated with multiorgan dysfunction, a soft-tissue infection with sepsis was suspected. Strains of streptococcus of serogroup B were isolated from specimens, taken from certain areas of the affected skin. After transferring the patient to our hospital the diagnosis of a B-streptococcal associated necrotizing fasciitis was confirmed. Despite intensive medical treatment and several surgical interventions the patient deceased due to an acute severe liver failure as a consequence of a secondarily developed septic shock. In comparison to the well-known cases caused by streptococcus group A, the B-streptococcal associated necrotizing fasciitis is a rather rare occurring disease.

[Recurrent respiratory tract infections]. / Rezidivierende Atemwegsinfekte.

On the occasion of a treatment of frequent infections of the upper respiratory tract an antibody deficiency syndrome was noticed in a 32-year-old female patient. Further investigations revealed a variable immunodeficiency syndrome, a disease belonging to the primary humoral immune defects and presenting with multiple clinical manifestations. Leading symptoms, however, are recurring respiratory infections that may lead to bronchiectasis. Therapy consists in the prevention of infections by periodical intravenous substitution with 7-S immunoglobulins and opportune prescription of antibiotics.

[Fever of unknown origin]. / Fieber unklarer Genese.

A 25-year-old patient presented with fever over a period of more than three months, night sweats, fatigue and a weight loss of more than 10 kg. A splenomegaly and an enlargement of cervical, thoracic and abdominal lymph nodes were found. The suspected malignant hematologic disorder could not be confirmed. Instead, epithelioid noncaseating granulomas in the bone marrow and a cervical lymph node as well as an elevated serum ACE and a lymphocytic alveolitis were found. These findings led us to the conclusion that the patient was suffering from sarcoidosis. Treatment with corticosteroids resulted in complete regression of all symptoms, including the splenomegaly and the enlargement of the lymph nodes. Sarcoidosis is an important consideration in differential diagnosis of fever of unknown origin, even in the absence of pathological changes on X-ray films of the chest.

[Polyuria, polydipsia]. / Polyurie, Polydypsie.

A 24 year old patient with epigastric pain, polyuria, polydipsia and hypercalcemia was admitted to the hospital. Besides the frequent causes of hypercalcemia such as primary hyperparathyroidism and malignancy-related hypercalcemia we had to consider sarcoidosis because of massive splenomegaly. The interstitial lung disease shown on x-ray films of the chest, the epithelioid granulomas in lung tissue and the increased ACE confirmed the diagnosis of sarcoidosis. Hypercalcemia is found in less than 5% of all cases with sarcoidosis. After treatment with steroids, diphosphonates and diuretics all symptoms and the hypercalcemia improved.

Induction of immediate-early genes by angiotensin II and endothelin-1 in adult rat cardiomyocytes.

OBJECTIVE: Few molecular signals for induction of myocardial hypertrophy have been identified. This study was carried out to investigate the action of angiotensin II and endothelin on the growth- and differentiation-related genes Egr-1 (early growth response gene 1) and c-fos in isolated adult rat cardiomyocytes. METHODS: Cardiac myocytes from male Wistar-Kyoto rats were isolated and incubated with angiotensin II and endothelin-1 in Dulbecco's modified Eagle's medium. RNA was isolated and blotted, and densitometric analysis was performed. All experiments were repeated at least three times. RESULTS: Endothelin-1 (10(-7) mmol/l) induced a 20-25-fold rise in Egr-1 messenger RNA within 15 min. This effect was dose-dependent. c-fos was induced 10-20-fold within 15 min with similar dose-response characteristics. Angiotensin II also induced Egr-1 and c-fos with kinetics similar to endothelin but a cofactor from fetal calf serum was needed for full c-fos expression. The protein kinase C activator phorbol 12-myristate 13-acetate also induced Egr-1. CONCLUSIONS: The results identify Egr-1 and c-fos as target genes for the action of endothelin and angiotensin II in the adult myocardium suggesting that induction of the genes may be part of the signal transduction pathway for angiotensin II and endothelin in the myocardium.