Biomedical subjects

C Preiss

Publications and source records attributed to C Preiss.

9 recordsLinked to original sources

PubMed2006

Endotherapy of Zenker's diverticulum using the needle-knife technique: long-term follow-up.

BACKGROUND AND STUDY AIMS: Endotherapy of Zenker's diverticulum by mucomyotomy of the bridge between the diverticulum and the esophageal lumen has been introduced as a promising alternative to surgical techniques. However the data on long-term clinical outcome are limited. After poor results in four patients treated by argon plasma coagulation, we studied the efficacy and the long-term outcome of dissection using a needle-knife in a consecutive series of patients. PATIENTS AND METHODS: Between December 2001 and November 2004, 31 consecutively treated symptomatic patients (18 men; median age 69 years; range 52-92) with Zenker's diverticulum were enrolled into this retrospective study. In all cases mucomyotomy was performed with a needle-knife with the patient under conscious sedation. The procedure was repeated in the case of incomplete relief from dysphagia or of recurrent symptoms during follow-up. All patients completed questionnaires on the frequency and severity of dysphagia, using a numeric analogue scale, ranging from 0 (never/none/excellent) to 10 (each time of swallowing/very severe/very bad). RESULTS: Endoscopic mucomyotomy was achieved in all 31 patients, with initial symptomatic improvement. Repeat treatment was required in 10 patients after a mean of 5.3 months, due to recurrence of symptoms. During a mean follow-up period of 26 months (range 14-49), 26 patients (84%) had long-term success of variable degree (65% with no or minimal remaining symptoms); four patients (13%) had insufficient relief and wanted a repeat treatment; and one patient (3%) underwent surgery. The success rate in the entire group was 84% (26/31) including those with repeat treatment, and 61% (19/31) if only success following a single treatment session was counted. Minor complications such as subcutaneous or mediastinal emphysema were observed in 23% and were conservatively managed. There were no major complications. CONCLUSIONS: A single needle-knife mucomyotomy procedure can achieve long-term symptomatic improvement in about two out of three cases of Zenker's diverticulum. The success rate can be increased to above 80% by repeated sessions. Minor complications occur frequently but they can be conservatively managed. Major complications were not observed. Further long-term studies are warranted to elucidate the role of endoscopy as a definitive single treatment, with determination of prognostic parameters for a successful long-term outcome.

Aged↗

PubMed2006

Evaluation of the pharmacokinetics of dalteparin in patients with renal insufficiency.

The pharmacokinetics of the low-molecular weight heparin (LMWH), dalteparin, was evaluated after a single intravenous bolus injection of 50 IU anti-Xa/kg in 8 healthy volunteers, 8 patients with moderate/severe renal failure (Cl(crea) 13.1-56.5 ml/min) and 8 hemodialysis patients. Venous blood samples were taken over a 1-day period to determine anti-Xa activity, anti-IIa activity and plasma levels of free tissue factor pathway inhibitor (free TFPI). Plasma anti-Xa and anti-IIa activities were measured using chromogenic assays and free TFPI levels using an ELISA technique. The anti-Xa clearance was significantly decreased (p < 0.05) in both groups with renal insufficiency when compared with healthy volunteers. There was a positive correlation between creatinine clearance and anti-Xa clearance in the healthy volunteers and patients with moderate/severe renal failure. The anti-Ila activity was characterized by 3- to 4-fold lower plasma concentrations and faster elimination compared with the anti-Xa activity. In patients with moderate/severe renal failure the elimination of anti-lla was only slightly decreased, whereas in hemodialysis patients anti-Ila clearance was significantly decreased (p < 0.01). There was no correlation between creatinine clearance and anti-IIa clearance. The baseline mean free TFPI plasma levels in the two groups with renal insufficiency were significantly higher (p < 0.01) than in healthy volunteers. Dalteparin administration induced a transient, 6.0- to 8.1-fold increase in the free TFPI values in the three study groups. Dalteparin induced an increase in C(max) and AUC(0 - infinity) values of free TFPI in the two groups with renal insufficiency that was higher than in healthy volunteers. No bleeding complications occurred during the study. In conclusion, this is the first report showing retarded elimination of dalteparin and enhanced free TFPI plasma levels induced by a LMWH in patients with renal insufficiency.

Adolescent↗

PubMed2003

A randomized trial of unsedated transnasal small-caliber esophagogastroduodenoscopy (EGD) versus peroral small-caliber EGD versus conventional EGD.

BACKGROUND AND STUDY AIMS: Unsedated esophagogastroduodenoscopy (EGD) has advantages over sedated EGD - e. g., prevention of side effects related to sedation, less patient monitoring, and less expense. This study compared the feasibility and tolerance of transnasal small-caliber (TSC-EGD) and peroral small-caliber EGD (PSC-EGD) with conventional EGD (C-EGD). PATIENTS AND METHODS: A total of 150 patients referred for diagnostic EGD were randomly allocated to undergo either TSC-EGD, PSC-EGD, or C-EGD under local anesthesia if they agreed to receive sedation only on demand or in case of intolerance. Patients, endoscopists, and nurses completed questionnaires on the tolerability and quality of the examinations using a visual analogue scale (VAS), ranging from 1 (best/nonexistent) to 10 (worst/unbearable) after EGD. Small-caliber EGD and C-EGD were performed with 5.9-mm and 9.8-mm video endoscopes (Olympus), respectively. RESULTS: The patients' age, sex, experience with EGD, and anxiety before EGD did not differ significantly between the three groups, each consisting of 50 patients. TSC-EGD failed in four of the 50 patients (8 %) because of a narrow nasal tract; they underwent PSC-EGD. Complete examinations, including the second part of the duodenum and biopsy sampling, were possible in all patients. Patients examined with an ultrathin instrument required sedation significantly less often (TSC-EGD 6 %, PSC-EGD 18 %, C-EGD 44 %; P < 0.01) and consequently spent less time in the recovery room. TSC-EGD was initially more painful on insertion, but caused less gagging (P<0.01) than peroral EGD during the whole procedure. TSC-EGD caused mild epistaxis in one case. CONCLUSIONS: TSC-EGD was carried out safely and completely in 92 % of the patients. TSC-EGD and PSC-EGD were better tolerated and required sedation less often than conventional EGD. Transnasal diagnostic EGD appears to be a promising alternative to peroral EGD, as it is associated with less gagging and a high level of patient satisfaction.

Adult↗

PubMed2001

Long-term follow-up of percutaneous transhepatic therapy (PTT) in patients with definite benign anastomotic strictures after hepaticojejunostomy.

BACKGROUND AND STUDY AIMS: Percutaneous transhepatic therapy (PTT) is a promising minimally invasive procedure for benign stenosis of the anastomosis after hepaticojejunostomy. In this prospective study, the effectiveness and safety of this technique were investigated. PATIENTS AND METHODS: Between October 1995 and May 2000 34 consecutive patients were referred for treatment of symptomatic cholestasis due to anastomotic strictures after hepaticojejunostomy. In all patients percutaneous transhepatic cholangioscopic (PTCS) drainage and bougienage of the stenosis up to 16 Fr were performed. Associated bile duct stones were fractured using PTCS laser lithotripsy and removed into the jejunum. Afterwards, patients received transhepatic drainage for 3 months initially. The tubes were replaced in case of persistent strictures every 3 months up to 1 year. Patients in whom treatment failed underwent surgery or received biliary metal stents, depending on risk factors and individual anatomy. RESULTS: The procedure was performed in 34 patients (mean age 57 +/- 15) with cholestasis (alkaline phosphatase 691 +/- 485 U/l, bilirubin level mean 3.2 +/- 3.1 mg/dl). The transhepatic tube was successfully positioned into the right hepatic bile duct (n = 25), into the left (n = 3), or into both (n = 3) after 4 +/- 1 sessions, except in two patients in whom an external drainage was used and another patient in whom the procedure had to be stopped due to a bleeding complication. In 14 patients bile duct stones were successfully treated by PTCS laser lithotripsy before the placement of a transhepatic tube. The 30-day morbidity and mortality rates were 23.5% and 0% respectively. In 23 patients, the transhepatic tube could be removed after 212 +/- 122 days, with no evidence of cholestasis during a further follow-up of 736 +/- 479 days. Four patients received metal stents because of persistent strictures after transhepatic intubation. Surgery had to be performed in a total of five patients, because of recurrent bile duct stones or recurrent strictures, in one patient with previous implantation of a metal stent, and in two patients with bile duct disconnection. Two patients died, one 1.5 years after surgery and one 427 days after metal stent implantation. None of these cases was related to the procedure. In two patients, the transhepatic tube is still in situ. CONCLUSIONS: Percutaneous transhepatic treatment of anastomotic strictures after hepaticojejunostomy is safe and highly effective in achieving internal biliary drainage. Temporary transhepatic intubation seems to be a promising minimally invasive alternative to surgery.

Adult↗

PubMed1999

[35-year-old patient with metastasized carcinoid of Vater's ampulla--case report and review of the literature].

We report the case of a 35-year-old female patient with a metastasized carcinoid of the papilla of Vater which is a rare lesion. 96 cases have been published in world literature previously. The carcinoid of the papilla of Vater appears typically as a hormone inactive tumor. It becomes symptomatic by cholestasis and jaundice in most cases and not by carcinoid-syndrome. An association with von Recklinghausen's disease as described in 25% of cases was not given in our patient. In contrast to the duodenal carcinoid there is no linear relationship between primary tumor size and incidence of metastases. The correct diagnosis was proven by histologic and immunohistochemical methods on specimen taken after endoscopic papillotomy. In spite of sensitive diagnostic methods like endosonography and somatostatin-receptor-scintigraphy exact staging was made intraoperatively in this case. Three months after pylorus pancreatoduodenal resection with lymphadenectomy the patient remained well with no evidence of tumor recurrence.

Adult↗

PubMed1997

Induction by staurosporine of nitric oxide synthase expression in vascular smooth muscle cells: role of NF-kappa B, CREB and C/EBP beta.

1. The effect of different protein kinase inhibitors on the expression of the inducible isoform of nitric oxide (NO) synthase (iNOS) was investigated in cultured vascular smooth muscle cells (VSMC) isolated from the rat aorta. 2. The non-selective protein kinase C (PKC) inhibitor, staurosporine, but not the more selective PKC inhibitors, calphostin C and Ro 31-8820, or the tyrosine kinase inhibitors, genistein and erbstatin analogue (erbstatin A), elicited a distinct (up to six fold) up-regulation of iNOS gene expression in these cells, as demonstrated by a parallel increase in iNOS mRNA and protein abundance as well as an accumulation of nitrite (NO2-) in the conditioned medium. Actinomycin D and cycloheximide inhibited the effect of staurosporine, suggesting an involvement of both DNA transcription and de nova protein synthesis. 3. Staurosporine also synergistically potentiated the stimulating effect of interleukin-1 beta (IL-1 beta), but not that of the adenylyl cyclase activator, forskolin, on NO2- production and iNOS protein abundance. Staurosporine, on the other hand, had no effect on the IL-1 beta-mediated increase in iNOS mRNA abundance. The effect of staurosporine on both basal and IL-1 beta-stimulated NO2- production was concentration-dependent with an apparent maximum at 3 nM. Among the other protein kinase inhibitors tested, only calphostin C also enhanced the stimulant effect of IL-1 beta approximately two fold, while genistein, erbstatin A and Ro 31-8220 inhibited rather than potentiated it. 4. Staurosporine did not influence basal activity of the transcription factors CREB and nuclear factor kappa B (NF-kappa B), but increased that of C/EBP. Moreover, staurosporine significantly augmented the activation of C/EBP by IL-1 beta and forskolin. 5. These findings suggest that in cultured VSMC a staurosporine-sensitive protein kinase exists, which is unlikely to be related to PKC, that prevents iNOS gene expression presumably by suppressing basal C/EBP activity. They also indicate that NF-kappa B and a member of the C/EBP family of transcription factors, presumably C/EBP beta, act synergistically under basal conditions and possibly also following exposure to IL-1 beta in the up-regulation of iNOS gene expression in these cells. Targeting of the activation of C/EBP beta may thus represent an interesting approach to interfere selectively with the cytokine-induced over-production of NO in acute and chronic inflammatory conditions.

Animals↗

PubMed1996

Antioxidants differentially affect nuclear factor kappa B-mediated nitric oxide synthase expression in vascular smooth muscle cells.

Increased 'oxidative stress' resulting in the activation of nuclear factor kappa B (NF-kappa B) is thought to play a crucial role in the cytokine-mediated expression of the inducible isoform of nitric oxide synthase (iNOS) in different cell types. Therefore, the effects of four different antioxidants, carbocromen, chrysin, 3,4-dichloroisocoumarin (DCI) and N-acetylserotonin (NAS), on iNOS expression were investigated in vascular smooth muscle cells (VSMC). All antioxidants strongly reduced the phorbol ester-stimulating superoxide anion formation in native VSMC. Carbocromen (200 microM) and chrysin (50 microM) had no effect, while NAS (1 mM) abolished the increase in nitrine production and iNOS protein abundance in cultured VSMC exposed to interleukin-1 beta (IL-1 beta, 60 U/ml) or the adenyl cyclase activator forskolin (10 microM). DCI also revealed a marked inhibitory effect in IL-1 beta-stimulated VSMC, but was less effective in cells treated with forskolin. DCI, but not NAS, also suppressed the activation of NF-kappa B in VSMC exposed to IL-1 beta, while no significant NF-kappa B activation was detected in forskolin-treated cells. These findings demonstrate that antioxidants differentially affect iNOS expression in VSMC both at the transcriptional level by preventing the activation of NF-kappa B and at the post-transcriptional level, presumably by promoting iNOS mRNA or protein degradation. They also suggest that reactive oxygen intermediates do not play a role in the activation of NF-kappa B by IL-1 beta in VSMC, and that transcription factors other than NF-kappa B mediate the induction of iNOS expression by elevating the intracellular concentration of cyclic AMP.

Animals↗

PubMed1996

Inhibition by antioxidants of nitric oxide synthase expression in murine macrophages: role of nuclear factor kappa B and interferon regulatory factor 1.

1. In view of the potential deleterious effects of high amounts of nitric oxide (NO) produced by the inducible isoform of NO synthase (iNOS) in inflammation, the prevention of the expression of this enzyme represents an important therapeutic goal. In cytokine-stimulated cells, activation of nuclear factor kappa B (NF-kappa B) is crucial for the increase in iNOS gene expression. Since NF-kappa B activation appears to involve a redox-sensitive step, we have investigated whether three structurally unrelated antioxidants, 5,7-dihydroxyflavone (chrysin), 3,4-dichloroisocoumarin (DCI) and N-acetyl 5-hydroxytryptamine (N-acetylserotonin, NAS), affect iNOS expression in cultured RAW 264.7 monocyte/macrophages stimulated with bacterial lipopolysaccharide (LPS, 140 ng ml-1) and interferon-gamma (IFN gamma, 5 u ml-1). 2. During a 6 h incubation period neither LPS nor IFN gamma alone exerted a significant effect but when combined, caused a prominent increase in nitrite formation, iNOS mRNA and protein abundance. Co-incubation with chrysin (50 microM), DCI (50 microM) or NAS (1 mM) markedly attenuated this increase in iNOS gene expression. 3. DCI, but not chrysin or NAS, prevented the activation of NF-kappa B in cells exposed to LPS plus IFN gamma for 30 min. In contrast, all three antioxidants significantly blunted the DNA-binding activity of interferon regulatory factor 1 (IRF-1), which mediates the synergistic effect of IFN gamma on iNOS gene expression in cells treated for 2 h with LPS plus IFN gamma. 4. DCI thus appears to inhibit iNOS gene expression at the transcriptional level by preventing the activation of both NF-kappa B and IRF-1. The inhibitory effect of DCI on NF-kappa B activation, however, does not seem to be related to its antioxidative properties, since DCI, unlike chrysin or NAS, is a potent serine protease inhibitor which stabilizes the inactive NF-kappa B complex by protecting the inhibitory I kappa B-alpha subunit from proteolytic degradation. 5. The virtually identical inhibitory effect of chrysin, DCI and NAS on the activation of IRF-1 points to a redox-sensitive step in the activation of this transcription factor, which in contrast to NF-kappa B requires de novo protein synthesis. 6. Since iNOS gene expression in human cells and tissues usually requires the combination of several cytokines, antioxidants such as chrysin and NAS which do not interfere with the activation of NF-kappa B may be of therapeutic value for selectively inhibiting the enhanced expression of this enzyme in inflammation.

Animals↗

PubMed1975

Effects of aging on basal levels of serum gonadotropins, ovarian compensatory hypertrophy, and hypersecretion of gonadotropins after ovariectomy in female rats.

Young adult (four months old) and old (14 months old) female rats were used in a series of experiments to determine the effects of aging on serum gonadotropin levels and on ovarian compensatory hypertrophy. Basal levels of gonadotropins were similar for rats of both ages. On the day after hemiovariectomy, serum FSH levels were elevated in both old and young rats. On that same day, serum LH levels were not elevated and the mean level for old rats was significantly lower than that for young rats. At two weeks and at two months after complete ovariectomy, the serum levels of both LH and FSH were lower in old than in young rats, suggesting imparied hypersecretion of gonadotropins in aged animals. After a suppressive dose of estradiol benzoate, ovariectomized old rats showed lower serum LH levels than did young ovariectomized rats. A comparison of the weights of ovaries removed two weeks after hemiovariectomy with those of the ovaries initially removed suggests that compensatory hypertrophy occurred in both groups of rats. However, ovarian weights, both before and after compensation, were lower in the old than in the young. After hemiovariectomy in old rats, the proportion of ovaries with corpora lutea increased, suggesting activation of some previously inactive ovaries.

Adaptation, Physiological↗