No inhibitor development after continuous infusion of factor concentrates in subjects with bleeding disorders undergoing surgery: a prospective study.

Inhibitor development against von Willebrand factor, factor VIII or factor IX is one of the most severe complications of treating patients with von Willebrand's disease (VWD), haemophilia A or haemophilia B respectively. Continuous infusion of factor concentrate has been implicated as a risk factor for inhibitor development. This prospective study investigated inhibitor development after continuous infusion of factor concentrate for surgical procedures in subjects with VWD or a severe form of haemophilia (factor activity <1%). Observations were made on the occurrence of inhibitor formation, adverse events and virus seroconversions. Main inclusion criteria comprised a negative history of inhibitors to replacement factor concentrate, ≥ 50 exposure days to factor concentrate and anticipated surgery requiring replacement factor coverage for ≥ 3 days. Therapy began with a bolus dose of 30-50 IU kg(-1) body weight of factor concentrate followed by continuous infusion with 3-4 IU kg(-1) h(-1) . Continuous infusion dose of factor concentrate was adjusted based on factor levels measured at least once daily. In 46 subjects included in the study to date, no inhibitors have been identified at discharge or follow-up (3-4 weeks after surgery), and no thrombotic events or postoperative wound infections occurred. All subjects underwent surgery without major blood loss, and hemostatic efficacy was generally rated 'excellent'. The results of the current study are promising, although the number of subjects is too small to make a definitive statement about the incidence of inhibitor development during continuous infusion of factor concentrate. Therefore, this study will be continued.

[Inhibitor development after early high exposure and cerebral haemorrhage. Costs and factor demand for a successful immunotolerance induction therapy]. / Inhibitorentwicklung nach früher hoher Exposition und Hirnblutung. Kosten einer erfolgreichen Immuntoleranztherapie.

Severe haemophilia A was diagnosed postpartum in a newborn. The mother was known as a conductor (intron 22 inversion) and an uncle had a persistently high titer inhibitor after failed ITI. Due to a cephalhaematoma, a high-dose pdFVIII substitution was given within the first days after birth. At the age of six month a severe cerebral haemorrhage occurred, making a high-dose pdFVIII substitution and neurosurgical intervention necessary. Several days later a porth-a-cath-system was implanted. The development of a high titer inhibitor occured six days later, an ITI was started according to the Bonn Protocol. Initially rFVIIa was given in addition to the pdFVIII substitution. Seven days after the beginning of treatment the inhibitor was no longer detectable. At monthly intervals the FVIII dosage was reduced until the dosage complied with a prophylaxis in severe haemophilia A. The duration of the ITI was nine months. A total of 30 mg rFVIIa and 276000 IU pdFVIII were used; costs in total: 280173.60 Euro.

[Gastrointestinal quality of life after duodenopancreatectomy in pancreatic carcinoma. Preliminary results of a prospective randomized study: pancreatoduodenectomy or pylorus-preserving pancreatoduodenectomy]. / Gastrointestinale Lebensqualität nach Duodenopankreatektomie beim Pankreascarcinom. Vorläufige Ergebnisse einer prospektiv-randomisierten Studie: PD vs PPPD.

BACKGROUND: The Whipple operation (PD) is the standard operation in patients with cancer of the head of the pancreas and the periampullary region. However, the pylorus-preserving duodenopancreatectomy (PPPD) is supposed to be superior in gastrointestinal function. METHODS: In a prospective randomized trial (October 1994-October 1998) PD and PPPD were compared in terms of global and gastrointestinal quality of life, operation time, duration of hospital stay, transfusions and perioperative morbidity. Quality of life was analyzed under standardized conditions (EORTC-QLQ-30) pre- and postoperatively (weeks 2, 6, 12, 24, 36, 48, and 60). RESULTS: A duodenopancreatectomy was performed in 48 patients because of cancer of the head of the pancreas (n = 38) and the periampullary region (n = 10) (PD, n = 24; PPPD, n = 24). The PD and PPPD groups did not differ according to age, gender or UICC stage. Operation time was shorter in the PPPD group (206 +/- 48 vs 306 +/- 54 min) (P < 0.05). Morbidity did not differ between the two groups (PPPD 20% vs PD 30%, P > 0.05). While there was no difference in global quality of life, gastrointestinal quality of life was postoperatively increased in the PPPD group regarding appetite, nausea and diarrhea (P < 0.05). While the preoperative body weight was reached after 6 months in 85% of the PPPD group (n = 20), this was true in only 60% of the PD-group (n = 14) (P < 0.05). CONCLUSION: PPPD seems to be associated with a better postoperative gastrointestinal quality of life than PD.

K-ras mutations in stools and tissue samples from patients with malignant and nonmalignant pancreatic diseases.

Mutant-enriched PCR and reverse dot blot hybridization in microplates were applied for examining K-ras status in stools and tissue samples from patients with pancreatic tumors and chronic pancreatitis. In tissue samples, K-ras mutations were found in 32 of 35 cases of ductal adenocarcinoma, in 5 of 7 periampullary cancers, in 1 cystadenocarcinoma, and in 3 of 5 patients with chronic pancreatitis. In stools, mutated K-ras was seen in 10 of 25 cases of ductal adenocarcinoma, in 1 case of cystadenocarcinoma, and in 2 of 6 cases of chronic pancreatitis. These data indicate that the K-ras status of stool samples may help identify pancreatic carcinoma and persons at risk for cancer development; however, it does not allow discrimination of malignant from nonmalignant diseases.

Elimination of apolipoprotein B48 formation in rat hepatoma cell lines transfected with mutant human apolipoprotein B cDNA constructs.

Rat hepatoma McA-RH7777 cell lines transfected with full-length human apolipoprotein (apo) B constructs produce mostly human apoB48 and only small amounts of apoB100, as a result of mRNA editing at codon 2153 (C to U conversion at nucleotide 6666). To abolish the formation of apoB48 and increase the yield of apoB100 and other forms of apoB longer than apoB48, site-specific mutations were introduced at or near the site of apoB mRNA editing. Among four mutations examined, only that in which codon 2153 was converted from CAA (Gln) to CTA (Leu) effectively precluded the formation of apoB48. In this mutant, a stop codon would not be generated even if the C to U conversion occurred. The three other mutations were introduced to disrupt the proposed stem-loop structure encompassing the editing site. Changes made in the third positions of five codons on the 5' side of the edited base or of four codons 3' of the edited base failed to eliminate the production of a protein with the approximate size of apoB48. A construct in which codon 2153 was changed from CAA to GAT (Asp) also failed to eliminate the production of a protein the size of apoB48. Analysis of the region between nucleotides 6200 and 6900 of the cDNA did not detect any prevalent alternate editing sites. Immunoblot analysis using polyclonal antibodies raised against synthetic peptides of human apoB100 indicated that the carboxyl terminus of the apoB48-like proteins probably resides between amino acid residues 2068 and 2129 of apoB100. These results provide some insight into the mechanism of apoB mRNA editing and will facilitate further studies on apoB-containing lipoproteins.

Characterization of tissue-specific enhancer elements in the second intron of the human apolipoprotein B gene.

We report the identification and characterization of tissue-specific transcriptional enhancer elements that influence the expression of the human apolipoprotein B gene. A 704-base pair PstI fragment comprising sequences from the first and second introns of the human apolipoprotein B gene (positions +360 to +1064) possesses tissue-specific transcriptional enhancer elements when assayed in transient transfection experiments using either the apolipoprotein B or thymidine kinase promoter. The majority of the enhancer activity, which was observed in transcriptionally active HepG2 and CaCo-2 cells, but not in transcriptionally inactive Chinese hamster ovary or HeLa cells, was subsequently localized to a 443-base pair SmaI-PvuII fragment (positions +621 to +1064) within the second intron of the apolipoprotein B gene. Gel retention experiments demonstrated that sequence motifs within this region interact with a number of nuclear proteins from HepG2, CaCo-2, and HeLa cells. The actual sequence elements that bound to nuclear proteins from HepG2 cells were identified by DNase I footprinting. Deletion experiments were performed to distinguish those protein-binding regions involved in the enhancer effect. Our data demonstrate that sequences between positions +806 and +940 are essential for this enhancer activity. This segment contains one large 97-base pair footprint, whose sequence has been conserved between the human and mouse genes. Binding sites for the liver-specific transcription factors HNF-1 and HNF-3 are present within this footprint.

Analysis of two different tandem repetitive elements within the human apolipoprotein B gene.

A large number of copies of the sequence (dTG-dAC)n, where n is between 10 and 60, exist in the human genome, and many are useful as polymorphic markers. One of these sequences occurs about 3 kilobases 5' of the human apolipoprotein (apo) B gene as seven distinguishable alleles containing from (TG)12 to (TG)18. This repeat is also present in the DNA of other primates. A second alternating purine-pyrimidine sequence with nine dinucleotide repeats and located in intron 4 is not polymorphic. Together with the apoB hypervariable repeat immediately 3' of the gene, the (TG)n sequence will provide a useful haplotype marker capable of distinguishing a large number of human apoB alleles, some of which may be associated with disease states.