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J Schönfeld

Publications and source records attributed to J Schönfeld.

13 recordsLinked to original sources
PubMed2003

Specific and sensitive detection of Ralstonia solanacearum in soil on the basis of PCR amplification of fliC fragments.

Ralstonia solanacearum is the causative agent of bacterial wilt in many important crops. A specific and sensitive PCR detection method that uses primers targeting the gene coding for the flagella subunit, fliC, was established. Based on the first fliC gene sequence of R. solanacearum strain K60 available at GenBank, the Ral_fliC PCR primer system was designed; this system yielded a single 724-bp product with the DNAs of all of the R. solanacearum strains tested. However, R. pickettii and four environmental Ralstonia isolates also yielded amplicons. The Ral_fliC PCR products obtained with 12 strains (R. solanacearum, R. pickettii, and environmental isolates) were sequenced. By sequence alignment, Rsol_fliC primers specific for R. solanacearum were designed. With this primer system, a specific 400-bp PCR product was obtained from all 82 strains of R. solanacearum tested. Six strains of R. pickettii and several closely related environmental isolates yielded no PCR product; however, a product was obtained with one Pseudomonas syzygii strain. A GC-clamped 400-bp fliC product could be separated in denaturing gradient gels and allowed us to distinguish P. syzygii from R. solanacearum. The Rsol_fliC PCR system was applied to detect R. solanacearum in soil. PCR amplification, followed by Southern blot hybridization, allowed us to detect about one target DNA molecule per PCR, which is equivalent to 10(3) CFU g of bulk soil(-1). The system was applied to survey soils from different geographic origins for the presence of R. solanacearum.

Base Sequence↗
PubMed1997

[Carcinoid syndrome. Recurrent upper abdominal pain, diarrhea and flush in a 15-year-old girl].

BACKGROUND: A carcinoid syndrome is typically diagnosed in elderly patients, median age at diagnosis was 60 years in two large series. We describe a patient with the carcinoid syndrome at the young age of 15 years. CASE REPORT: The 15-year-old patient's history and findings on physical examination, clinical chemistry, abdominal ultrasound and liver biopsy were typical for a carcinoid with hepatic metastases. The patient's age, however, was very unusual. Because of her youth, we discussed a potentially curative treatment with resection of the primary tumor in the upper jejunum followed by liver transplantation at a second operation. This concept had to be abandoned, when the first operation revealed a tumor in the mesenterium, close to the primary, 5 cm in diameter and around the superior mesenteric artery. This tumor could not be resected. Liver transplantation therefore did not offer this young patient a chance for cure.

Abdominal Pain↗
PubMed1997

Effect of viscous fiber (guar) on postprandial motor activity in human small bowel.

Both caloric value and chemical composition of a meal have been shown to regulate postprandial small bowel motility in dog. In the same species, duration of and contractile activity within the postprandial period also depends on mean viscosity. It is unknown, however, whether meal viscosity and fiber content also regulate small bowel motor activity in man. In human volunteers, we therefore studied the effect of guar gum on small bowel motor response to liquid and solid meals. Twenty-six prolonged ambulatory small bowel manometry studies were performed in 12 volunteers. A total of 620 hr of recording were analyzed visually for phase III of the MMC and a validated computer program calculated the incidence and amplitude of contractions after ingestion of water (300 ml), a pure glucose drink (300 ml/330 kcal) or a solid meal (530 kcal) with and without 5 g of guar gum. Addition of 5 g of guar gum did not significantly delay reappearance of phase III after ingestion of water (59 +/- 11 vs 106 +/- 21 min; P = 0.09). However, guar gum significantly prolonged duration of postprandial motility pattern both after the glucose drink (123 +/- 19 vs 199 +/- 24 min; P < 0.05) and after the solid meal (310 +/- 92 vs 419 +/- 22 min; P = 0.005). Contractile activity during these periods was not affected by guar gum. This was true for mean incidence of contractions after water (1.9 +/- 0.3 vs 1.8 +/- 0.5 min-1), after the glucose drink (1.6 +/- 0.4 vs. 1.7 +/- 0.3 min-1) and after the solid meal (2.4 +/- 0.4 vs 2.6 +/- 0.4 min-1). Likewise, mean amplitude of contractions was not affected by guar gum after water (22.8 +/- 1.4 vs 20.9 +/- 1.9 mm Hg), after the glucose drink (20.5 +/- 1.4 vs 21.3 +/- 1.2), and after the solid meal (20.3 +/- 1.5 vs 21.5 +/- 1.6 mm Hg). Thus a guar gum-induced increase in chyme viscosity markedly prolonged duration of postprandial motor activity in the human small bowel. Contractile activity within the postprandial period, however, was not affected. We suggest that the postprandial motility pattern persisted longer after the more viscous meals, because gastric emptying and intestinal transit were delayed by guar gum. We conclude that it is essential to define meal viscosity and fiber contents when studying postprandial small bowel motility.

Adult↗
PubMed1997

Daytime and night time motor activity of the small bowel after solid meals of different caloric value in humans.

BACKGROUND: Meals disrupt the interdigestive pattern of small bowel motor activity and convert it into the postprandial pattern. Previous studies have shown that duration of postprandial motor activity depends on the caloric value of a meal, but results from two recent human studies suggested that there is a caloric ceiling, above which an additional increase in the caloric load fails to prolong the postprandial period further. AIM: To investigate the hypothesis of a caloric ceiling by studying daytime motor activity of the human small bowel in response to five solid meals, covering a wide range of calories. METHODS: Eight healthy male volunteers underwent five separate, ambulatory small bowel manometry studies and had a total of 80 meals. For lunch, volunteers ate between one and five portions of a solid meal (220, 440, 660, 880, or 1100 kcal). Ten hours later and 30 minutes before they went to bed, they ate either two or four portions of the same meal (440 kcal or 880 kcal). Recordings were analysed visually for phase III of the migrating motor complex and a validated computer program calculated incidence and amplitude of contractions. RESULTS: Apart from two versus three portions (440 kcal v 660 kcal), postprandial motor activity was significantly prolonged by each 220 kcal increase in the caloric load of the lunch (168 (SEM 14), 305 (22), 298 (23), 368 (36), and 398 (38) min). Mean incidence of contractions was significantly different only between the two extremes tested: 220 kcal and 1100 kcal (2.9 (0.3) v 4.5 (0.6) min-1). Amplitude of contractions did not depend on meal size. Daytime and night time postprandial activity were not significantly different. This was true for duration of fed activity, as well as mean incidence and amplitude of contractions during the postprandial period. CONCLUSION: Caloric value of a meal regulates duration of the fed activity in the human small bowel over a wide range of calories, and-for caloric loads up to 1100 kcal-there is no maximum duration of postprandial motor activity. Furthermore the postprandial small bowel motor activity is very similar between daytime and night time.

Adult↗
PubMed1996

[Primary sclerosing cholangitis: conventional and quantitative liver function tests during long-term therapy with ursodeoxycholic acid].

Primary sclerosing cholangitis, a chronic cholestatic liver disease, frequently leads to an impairment of liver function. In nine men and two women, aged 23 to 57 years, we prospectively studied for three to six years the effect of treatment with ursodeoxycholic acid (UDCA) on liver function. 10 mg UDCA/kg bw significantly reduced serum activities of AP, gamma GT, AST and ALT for several years. After three years of treatment, however, serum concentration of bilirubin was higher than before therapy in eight out of eleven patients (1.8 +/- 0.8 versus 0.9 +/- 0.1 mg/dl; p = 0.01). Likewise, serum concentration of bilirubin was higher in eight out of nine patients after four years of treatment (1.3 +/- 0.3 versus 0.9 +/- 0.1 mg/dl; p = 0.03). In most cases, however, the increase was discrete. Parameters of synthetic liver function (coagulation, serum protein concentration, serum activity of cholinesterase) remained constant in the observation time. Quantitative liver function tests (galactose elimination capacity and indocyanine green half-life) also showed little variation in the observation time. We conclude that UDCA treatment significantly improves serum activities of liver enzymes for several years. Nevertheless, serum bilirubin concentration, believed to be of prognostic value in patients with PSC, seems to rise slowly over time. Serial determinations of galactose elimination capacity and indocyanine green halflife are not superior to conventional liver function tests in the timing of liver transplantation in the individual patient.

Adult↗
PubMed1985

Studies on the role of sodium- and potassium-activated adenosine triphosphatase inhibition in the pathogenesis of human hypertension. Changes in vascular and cardiac function following inhibition of the sodium pump in normotensive subjects and effects of calcium entry blockade.

An endogenous humoral factor which inhibits the sodium- and potassium-activated adenosine triphosphatase (Na-K-ATPase) enzyme in vitro has been incriminated recently of playing a pathogenetic role in experimental and human hypertension. The present study was therefore performed in six healthy volunteers to investigate the hemodynamic consequences of an inhibition of this enzyme by ouabain, a potent and specific inhibitor of Na-K-ATPase. In addition, the role of intracellular calcium as a potential mediator was studied indirectly by the administration of nifedipine, a potent calcium entry blocker with predominant vasodilator properties. Intravenous administration of 8.5 micrograms ouabain/kg body weight inhibited red blood cell (RBC) - Na-K-ATPase by 49% which was accompanied by a significant increase in RBC - ATP and a decrease in intracellular potassium concentrations. This enzyme inhibition resulted in a 24% increase in peripheral vascular resistance. The parallel decrease in cardiac output and heart rate, however, prevented a rise in arterial pressure. This increase in vascular resistance was completely abolished by pretreatment with nifedipine (10 mg orally). In the absence of an effect of nifedipine on Na-K-ATPase, its attenuation of the vasoconstrictor effect of ouabain suggests that the effects of ouabain on the vascular smooth muscle cell are mediated by intracellular calcium. These results demonstrate that inhibition of the Na-K-ATPase enzyme in vivo causes a marked peripheral vasoconstriction. They are also compatible with the concept that an endogenous inhibitor of Na-K-ATPase - in the presence of decreased baroreceptor reflex sensitivity due to blood volume expansion - may play a role in the pathogenesis of human arterial hypertension.

Adenosine Triphosphate↗
PubMed1975

Alpha-fetoprotein in a patient with embryonal cell carcinoma of the testes.

A case of embryonal cell carcinoma of the testes with widespread metastases, and the presence of AFP in the patient's serum, is reported. The usefulness of the detection of AFP for the diagnosis of this type of tumor is stressed. The use of polyacrylamide disc electrophoresis in combination with double-diffusion in gel are considered as a highly sensitive method for the detection of AFP in routine clinical work. The literature dealing with the characterization of AFP and its frequency and significance in various diseases is reviewed.

Blood Proteins↗