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J Graff

Publications and source records attributed to J Graff.

At least 55 records · Page 3Linked to original sources
PubMed1994

Mutational events in consecutive passages of hepatitis A virus strain GBM during cell culture adaptation.

In order to study the adaptation of hepatitis A virus (HAV) in cell culture, we examined the mutational events of the genome in early passages of HAV strain GBM propagated either in FRhK-4 cells (fetal rhesus monkey kidney-derived) or in human embryonic kidney (HEK) and human embryonic fibroblast cells (HFS) in relation to their growth characteristics. Sequence analysis of the nucleotide region encoding 2B, 2C, and the beginning of 3A as well as the nucleotide region encompassing the 5' noncoding region (5'NCR) of the genome was performed on consecutive virus passages after amplification of the viral RNA from the cell culture supernatant by antigen-capture PCR. By the 2nd passage of the GBM variants cultured in FRhK-4 or in HEK cells we found a mutation at nucleotide position 3889 (2B coding region) which results in an amino acid substitution from alanine to valine. Further mutations present in the 2B/2C region of the cell culture-adapted GBM variants differ from each other and occur after the 10th or even the 40th virus passage. Another early change, an in frame deletion of nine nucleotides in the 3A region, appeared in the 5th virus passage only in GBM cultured on FRhK-4 cells. This genome region showed different mutations in the virus passages on HEK and HFS cells. The 5'NCR of the cell culture-adapted GBM variants, in contrast, did not show any mutations before the 8th virus passage. The faster and more efficient growth of the HAV strain GBM during successive propagation on cell cultures seems to correlate with the appearance of mutations in the investigated genome regions.

Adaptation, Physiological↗
PubMed1994

Transperitoneal transport of creatinine. A comparison of kinetic models.

Six kinetic models of transperitoneal creatinine transport were formulated and validated on the basis of experimental results obtained from 23 non-diabetic patients undergoing peritoneal dialysis. The models were designed to elucidate the presence or absence of diffusive, non-lymphatic convective and lymphatic convective solute transport. The validation procedure included an assessment of theoretical (a priori) and practical (a posteriori) identifiability, goodness of fit, residual error analysis and plausibility of parameter estimates. The results of the validation procedure demonstrate that the model including all three forms of transport is superior to other models. We conclude that the best model of transperitoneal creatinine transport includes diffusion, non-lymphatic convective transport and lymphatic convective transport.

Adult↗
PubMed1994

Nucleotide sequence of wild-type hepatitis A virus GBM in comparison with two cell culture-adapted variants.

In order to study cell tropism and attenuation of hepatitis A virus (HAV), the genome of HAV wild-type GBM and two cell culture-adapted variants, GBM/FRhK and GBM/HFS, were cloned and sequenced after amplification by reverse transcriptase-PCR. During virus cultivation, the HAV variant GBM/FRhK had a strict host range for FRhK-4 cells, in contrast to GBM/HFS, which can be grown in HFS and FRhK-4 cells. The HAV variant GBM/HFS was shown to be attenuated when inoculated into chimpanzees (B. Flehmig, R. F. Mauler, G. Noll, E. Weinmann, and J. P. Gregerson, p. 87-90, in A. Zuckerman, ed., Viral Hepatitis and Liver Disease, 1988). On the basis of this biological background, the comparison of the nucleotide sequences of these three HAV GBM variants should elucidate differences which may be of importance for cell tropism and attenuation. The comparison of the genome between the GBM wild type and HAV wild types HM175 (J. I. Cohen, J. R. Ticehurst, R. H. Purcell, A. Buckler-White, and B. M. Baroudy, J. Virol. 61:50-59, 1987) and HAV-LA (R. Najarian, O. Caput, W. Gee, S. J. Potter, A. Renard, J. Merryweather, G. Van Nest, and D. Dina, Proc. Natl. Acad. Sci. USA 82:2627-2631, 1985) showed a 92 to 96.3% identity, whereas the identity was 99.3 to 99.6% between the GBM variants. Nucleotide differences between the wild-type and the cell culture-adapted variants, which were identical in both cell culture-adapted GBM variants, were localized in the 5' noncoding region; in 2B, 3B, and 3D; and in the 3' noncoding region. Our result concerning the 2B/2C region confirms a mutation at position 3889 (C-->T, alanine to valine), which had been shown to be of importance for cell culture adaptation (S. U. Emerson, C. McRill, B. Rosenblum, S. M. Feinstone, and R. H. Purcell, J. Virol. 65:4882-4886, 1991; S. U. Emerson, Y. K. Huang, C. McRill, M. Lewis, and R. H. Purcell, J. Virol. 66:650-654, 1992), whereas other mutations differ from published HAV sequence data and may be cell specific. Further comparison of the two cell culture-adapted GBM variants showed cell-specific mutations resulting in deletions of six amino acids in the VP1 region and three amino acids in the 3A region of the GBM variant GBM/FRhK.

Adaptation, Biological↗
PubMed1994

Sequence variability of hepatitis A virus and factor VIII associated hepatitis A infections in hemophilia patients in Europe. An update.

Outbreaks and sporadic cases of hepatitis A have been observed in 4 European countries in hemophilia patients receiving factor VIII preparations. PCR amplification of potential hepatitis A virus (HAV) nucleic acid present in plasma pools, purified factor VIII and acute-phase sera from infected individuals has been performed and the nucleic acid sequence determined for those samples that resulted in a positive PCR product. HAV sequences were detected in the serum of 2 German patients, but not in the factor VIII lots administered to these individuals. Screening of plasma pools and the corresponding 5 lots of factor VIII associated with the outbreak in Ireland did not reveal any HAV sequences. In contrast, a study of samples from Italy detected HAV sequences in 5 of 12 lots and in 2 hemophilia patients who developed hepatitis A. These data suggest that implicated factor VIII preparations might have been involved in the outbreaks of HAV infection among Italian hemophiliacs. However, no molecular evidence was obtained for a similar association in Germany or Ireland. The preliminary data from these two investigations must be verified by animal inoculation studies and supported by epidemiologic analysis.

Base Sequence↗
PubMed1994

Detection of hepatitis A virus in a factor VIII preparation by antigen capture/PCR.

The antigen capture/PCR (AC/PCR) has been applied in the analysis of various factor VIII preparations, which were suspected to be contaminated with hepatitis A virus (HAV). AC/PCR involves capturing the antigen, i.e. the intact virus particles, by binding to the HAV monoclonal antibody mAb 7e7, reverse transcription of the viral RNA and amplification of the cDNA with HAV-specific primer pairs. The PCR analysis of one factor VIII concentrate yielded an HAV-specific DNA product, which could be confirmed by Southern blot analysis. The HAV strain recovered by AC/PCR from this factor VIII concentrate could be classified into genotype III after solid-phase sequencing of the product and comparison with the consensus sequences for the known HAV genotypes. Analysis of the sera from 3 haemophiliacs treated with this batch has not resulted in a reliable product. However, the results obtained indicate that HAV can be detected in purified factor VIII preparations by AC/PCR.

Base Sequence↗
PubMed1993

Detection of hepatitis A virus in sewage sludge by antigen capture polymerase chain reaction.

Antigen capture polymerase chain reaction (PCR) was tested as a sensitive and rapid method for detecting hepatitis A virus (HAV) in raw sewage sludge. The antigen capture PCR was performed both with and without solid-phase virus-catching monoclonal antibodies. Similar results proved that both methods were equally sensitive. Sewage sludge samples from different regions in Germany were examined for evidence of HAV contamination by antigen capture PCR. This method of detection was compared with that used in a previous study of these sewage sludge samples, in which the HAV was detected through indirect immunofluorescence after cell culture inoculation. The results obtained by antigen capture PCR matched those obtained in the earlier cell culture investigations, when HAV was detected in raw as well as digested sewage sludge samples. The advantage of the PCR method, however, lies in the fact that it needs only two days while the cell culture propagation of HAV takes about 8 to 10 weeks.

Antibodies, Monoclonal↗
PubMed1992

Comparison of Bay K 8644, nitrendipine and atropine on spontaneous and pelvic-nerve-induced bladder contractions on rat bladder in vivo.

The effects of the dihydropyridine-type calcium antagonist (nitrendipine) and agonist (Bay K 8644) in comparison to atropine have been studied after intravenous administration on spontaneous and pelvic-nerve-induced contraction of rat urinary bladder. Bay K 8644 increased the basal internal bladder pressure as well as the amplitude of the spontaneous bladder contractions in a dose-dependent manner. In addition, an increase in systemic arterial blood pressure was noted for a period of about 20 min. In the presence of atropine the effects of Bay K 8644 on the urinary bladder were almost completely antagonized. Both nitrendipine and atropine reduced in a dose-dependent manner the amplitude of spontaneous and nerve-induced bladder contraction. The spontaneous and nerve-induced bladder contractions were significantly reduced by atropine or nitrendipine. Only nitrendipine caused a reduction of the spontaneous bladder contraction frequency. The systemic blood pressure was decreased significantly by nitrendipine but not after atropine administration. We suggest that both calcium antagonist and agonist can change the tension of the urinary bladder in vivo. As a side-effect the systemic blood pressure is altered. Atropine can antagonize the effect of BayK 8644 on the urinary bladder and reduces spontaneous and nerve-induced bladder contractions more specifically than nitrendipine.

3-Pyridinecarboxylic acid, 1,4-dihydro-2,6-dimethy↗
PubMed1992

Influence of papaverine on rat bladder contractions in vivo.

In an acute rat model (in vivo) spontaneous rhythmic bladder contractions were induced by ligation of the urethra. In addition single bladder contractions were recorded during neurostimulation of the pelvic nerve. Spontaneous and electrically induced bladder contractions were sensitive to papaverine and isoprenaline in vivo. The basal bladder pressure and bladder contraction parameters were reduced more potently by isoprenaline. Blood pressure decreased significantly after isoprenaline injection (0.5-50 micrograms/kg = 4.73 x 10(-6)-4.73 x 10(-4) mol/l) and high concentration of papaverine (5 mg/kg = 2.95 x 10(-2) mol/l). Compared to isoprenaline papaverine was less toxic. These results are different to previous in vitro investigations in rat bladder strips. In vivo papaverine seems to be less effective on nerve-mediated bladder contractions and decreases bladder pressure. Our results indicate that beta-adrenergic receptors play a potent role in the inhibition of spontaneous and pelvic nerve-induced bladder contraction.

Animals↗
PubMed1992

An assessment of the flow rate within peritoneal dialysis catheters, using a standardized in vitro technique.

A variety of peritoneal dialysis catheters are used in clinical practice. The catheters are mainly described by their design, French number (circumference in mm) and length. However, this description does not provide information about the catheters inflow and outflow rates. We have therefore, studied flow rates of 18 adult catheters, using a uroflowmeter. Inflow rates were measured with the inflow bag 100 cm and 145 cm above the tip of the catheter, and outflow rates were measured with the flow transducer located 35 cm and 80 cm below the tip of the catheter, imitating situations where patients are sitting in a chair or laying in a bed during fluid exchanges. Ten measurements were made for each catheter at all heights. We found that catheter designs do affect flow rates. Straight catheters had statistic significantly faster inflow and outflow rates compared to curled catheters (p < 0.001). Moreover, curled catheters had statistic significantly faster flow rates than Swan Neck catheters (p < 0.001). The length and internal diameter of the catheter was found to be the determining factor for the differences in flow rates.

Catheterization↗
PubMed1992

Interferon-alpha 2b instillation prophylaxis in superficial bladder cancer--a prospective, controlled three-armed trial. Project Group Bochum--Interferon and Superficial Bladder Cancer.

Sixty-seven patients with recurrent pTa G1-G3 to pT1 G1-G3 tumors were randomized into three groups receiving either Intron A at 10 MU/instillation, Intron A at 10 MU and mitomycin C (MMC) at 20 mg/instillation or MMC at 20 mg/instillation. After a mean follow up of 6.2 months no tumor recurrence has been seen in the group receiving combined therapy, whilst four out of 22 in the interferon group and five out of 23 in the MMC group suffered a recurrence. Side effects were slight. These preliminary results suggest that a combination of the two drugs is more effective than either drug alone.

Aged↗
PubMed1991

[Analgesia using oral administration of tilidine naloxone for extracorporeal shockwave lithotripsy. A double blind study].

Reduction in pain perception during ESWL due to a technical modification of the lithotriptor was expected and prompted a reassessment of anaesthesia techniques for ESWL. In this study the need for analgesic treatment had to be investigated. After satisfactory preliminary results in a previous pilot study, the value of the oral combination of the anti-anxiety drug dipotassium clorazepate on the evening before ESWL together with the analgesic tilidine-naloxone before treatment was tested in a randomised double-blind study in 120 patients. In case of intolerable pain during the treatment all patients were free to ask for additional intravenous analgesic medication (fentanyl). During ESWL, 28.3% of the tilidine-N group patients and 6.7% of the placebo group were pain-free, whereas intolerable pain was reported by 30% of the tilidine-N group and 56.7% of the placebo group. Therefore, 70% of the tilidine-N group patients were treated without any additional analgesic or sedative medication. The good experience with this oral anaesthesia approach, the lack of significant side effects and a good acceptance by the patients warrant further recommendation of this technique.

Administration, Oral↗
PubMed1990

[Emergency coronary surgery in patients with unstable angina pectoris. Results and place in the total concept of the treatment of this group of patients].

The urgent coronary surgery performed in patients with high risk unstable angina (rest pain greater than 48 h) shows still different results. We found in 57 urgent operated patients the same functional and clinical results as after elective bypass grafting. A higher in hospital mortality after urgent coronary surgery based on a higher number of grafts are occluded in the early postoperative period. The better prognosis concluded that the use of urgent coronary surgery is the therapy of choice in patients with refractory unstable angina pectoris.

Adult↗
PubMed1989

Influence of iloprost on eicosanoid generation and lipid levels in experimental myocardial ischemia in dogs.

Anaesthetized mongrel dogs were subjected to occlusion of a coronary artery. The resulting myocardial infarction was observed for three hours. One hour after occlusion, infusion of the stable prostacyclin analogue iloprost or saline was started. In the control group myocardial infarction was associated with an increase of the ratio TXB2/6-keto-PGF1a which was abolished by iloprost treatment. After occlusion in the control group, the atherosclerosis index (TC-HDLC): HDLC was increased, but in the iloprost-treated group it was significantly decreased. The results of this study suggest that the administration of iloprost is able to prevent changes in eicosanoid metabolism and lipoprotein pattern after coronary artery occlusion in dogs.

6-Ketoprostaglandin F1 alpha↗