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Dive into the research topics where Raymond S. Koff is active.

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Featured researches published by Raymond S. Koff.


The Lancet | 1996

Risk of aspirin-associated major upper-gastrointestinal bleeding with enteric-coated or buffered product

Judith P. Kelly; David W Kaufman; Jan M. Jurgelon; Jane E. Sheehan; Raymond S. Koff; Samuel Shapiro

BACKGROUNDnAspirin products are known to cause irritation and injury to the gastric mucosa. The belief that enteric-coated and buffered varieties are less likely to occasion major upper-gastrointestinal bleeding (UGIB) than plain aspirin was tested in data from a multicentre case-control study.nnnMETHODSn550 incident cases of UGIB admitted to hospital with melaena or haematemesis and confirmed by endoscopy, and 1202 controls identified from population census lists, were interviewed about use of aspirin and other non-steroidal anti-inflammatory drugs (NSAIDs) during the 7 days before the onset of bleeding (cases) or interview (controls). Relative risks of UGIB for each type of aspirin used regularly (at least every other day) were calculated overall, and according to dose, by multiple logistic regression, with control for age, sex, marital status, date, education, cigarette smoking, alcohol use, and use of NSAIDs.nnnFINDINGSnThe relative risks of UGIB for plain, enteric-coated, and buffered aspirin at average daily doses of 325 mg or less were 2.6, 2.7, and 3.1, respectively. At doses greater than 325 mg, the relative risk was 5.8 for plain and 7.0 for buffered aspirin; there were insufficient data to evaluate enteric-coated aspirin at this dose level. There were no important differences in risk attributable to the three aspirin forms according to bleeding site (gastric vs duodenal), or when users of NSAIDs were excluded.nnnINTERPRETATIONnUse of low doses of enteric-coated or buffered aspirin carries a three-fold increase in the risk of major UGIB. The assumption that these formulations are less harmful than plain aspirin may be mistaken.


Clinical Pharmacology & Therapeutics | 1993

Nonsteroidal anti‐inflammatory drug use in relation to major upper gastrointestinal bleeding

David W Kaufman; Judith P. Kelly; Jane E. Sheehan; András Laszlo; Bengt-Erik Wiholm; Lars Alfredsson; Raymond S. Koff; Samuel Shapiro

In a study in the United States, Sweden, and Hungary, 335 cases of gastric bleeding without predisposing factors were compared with 670 control subjects, and 239 cases of duodenal bleeding were compared with 489 control subjects. For aspirin taken at least every other day during the week before the onset of bleeding (regular use), the relative risk of gastric bleeding was 4.4 (95% confidence interval [CI], 2.9 to 6.7); for occasional use, it was 3.3 (95% CI, 2.1 to 5.0). For ibuprofen, the corresponding estimates were 1.0 (95% CI, 0.4 to 2.6) and 1.1 (95% CI, 0.5 to 2.4). For naproxen, the estimate for regular use was 4.0 (95% CI, 1.5 to 11). The estimates for any use of piroxicam (crude estimate), indo‐methacin, and diclofenac during the week before onset were 18 (95% CI, 4.1 to 83), 1.6 (95% CI, 0.4 to 5.9), and 0.9 (95% CI, 0.2 to 4.2), respectively. The corresponding relative risks of duodenal bleeding were 7.1 (95% CI, 4.2 to 12) and 2.2 (95% CI, 1.3 to 3.7) for the regular and occasional use of aspirin, 2.4 (95% CI, 0.5 to 11) and 0.8 (95% CI, 0.3 to 2.0) for ibuprofen, 12 (95% CI, 2.8 to 54) and 9.9 (95% CI, 2.3 to 44) for naproxen, 17 (95% CI, 3.6 to 79) for any use of piroxicam (crude estimate), and 1.7 (95% CI, 0.2 to 14) for any use of indomethacin. There was a significant trend in the risk of gastric bleeding with increasing dose of regular aspirin use (p = 0.002). The relative risk estimates for the regular use of 325 mg or less were significantly elevated for both gastric and duodenal bleeding at 3.1 and 6.4, respectively.


The American Journal of Gastroenterology | 1999

The risk of acute major upper gastrointestinal bleeding among users of aspirin and ibuprofen at various levels of alcohol consumption

David W Kaufman; Judith P. Kelly; Bengt-Erik Wiholm; András Laszlo; Jane E. Sheehan; Raymond S. Koff; Samuel Shapiro

Objective:Major upper gastrointestinal bleeding (UGIB) is the most important adverse effect of aspirin and other nonsteroidal anti-inflammatory drugs (NSAIDs). Alcoholic beverages also precipitate UGIB. This analysis was conducted to evaluate whether the deleterious effects of NSAIDs are further increased among drinkers.Methods:An interview-based, case-control study was conducted in the U.S. and Sweden; 1224 patients hospitalized with acute major UGIB due to newly occurring peptic ulcer or gastritis were compared to 2945 neighbor controls.Results:Compared with those who drank less than one drink/wk, the relative risk of acute UGIB increased with increasing alcohol consumption, rising to 2.8 among those who drank ≥21 drinks/wk. Among current drinkers, the relative risk of acute UGIB due to the use of aspirin was raised at all levels of alcohol consumption; the estimate for aspirin taken at least every other day (regular use) at doses of >325 mg among all current drinkers combined was 7.0; for regular use at lower doses, the corresponding estimate was 2.8, and for any occasional use, it was 2.4. All estimates were statistically significant. Data for ibuprofen were more limited, but the relative risk estimates did not appear to vary consistently with level of alcohol consumption. For regular use (all doses combined), the estimate among all drinkers combined was significantly elevated, at 2.7; occasional ibuprofen use was not associated with UGIB (1.2). There were insufficient data to evaluate other NSAIDs according to alcohol consumption.Conclusions:The findings suggest that acute UGIB is similarly associated with the use of the two most common nonprescription NSAIDs, aspirin and ibuprofen, at all levels of alcohol consumption. As heavy alcohol intake independently increases the risk, the incidence of UGIB is highest among persons who are both heavy drinkers and users of aspirin or ibuprofen.


Vaccine | 1992

Clinical manifestations and diagnosis of hepatitis A virus infection

Raymond S. Koff

Hepatitis A is an acute, necroinflammatory disease of the liver which results from infection by the hepatitis A virus (HAV). The mean incubation period is approximately 30 days. Although the disease is usually self-limited, the severity of illness is age-dependent. In children, hepatitis A is usually asymptomatic, while in adults, symptomatic infection is characteristic and jaundice is common. Fulminant hepatitis A is rare and is also age-dependent. The onset of hepatitis A is often abrupt and characteristic prodromal symptoms are followed, within a few days to a week, by dark urine and jaundice. Mild to moderate tenderness over an enlarged liver is usually detected. Serum alanine and aspartate aminotransferase levels usually both rise rapidly during the prodromal period, reach peak levels and then decrease by approximately 75% per week. Serum bilirubin concentrations reach peak levels later and decline less rapidly than serum aminotransferases. Nonetheless, the period of jaundice persists for < 2 weeks in approximately 85% of cases. Nearly all adult patients with clinically apparent disease experience complete clinical recovery with restoration of normal serum bilirubin and aminotransferase values by 6 months. Relapses and prolonged cholestasis are unusual manifestations of hepatitis A, and even in these circumstances, recovery is the rule and chronic hepatitis is not seen. The diagnosis of hepatitis A requires the detection of immunoglobulin M antibody to HAV in a patient who presents with, or has recently had, clinical features of hepatitis (icteric or anicteric disease) or in an individual with inapparent, asymptomatic infection in whom serum aminotransferase elevations may be detected.(ABSTRACT TRUNCATED AT 250 WORDS)


The American Journal of Medicine | 1993

Immunogenicity of two recombinant hepatitis B vaccines in older individuals

Thomas L. Treadwell; Emmet B. Keeffe; John R. Lake; A.E. Read; Lawrence S. Friedman; Ira S. Goldman; Charles D. Howell; Maria deMedina; Eugene R. Schiff; Donald M. Jensen; Raymond S. Koff

PURPOSEnCurrently available hepatitis B vaccines are recombinant, yeast-derived preparations given in 10-micrograms or 20-micrograms doses. The optimum dose remains controversial. We sought to assess the relative immunogenicity of two hepatitis B vaccines, given in different doses, in older individuals.nnnPATIENTS AND METHODSnIn a multicenter, double-blind, randomized clinical trial, a total of 460 healthy subjects between 39 and 70 years of age were screened and immunized with either Engerix-B 20 micrograms or Recombivax HB 10 micrograms in standard, intramuscular, 3-dose regimens. Of these, 397 subjects were eligible to continue vaccination. Immunogenicity was measured by determination of antibody to hepatitis B surface antigen (anti-HBs). Seroconversion and seroprotection rates, and geometric mean titers of anti-HBs were calculated at 1, 3, 6, and 8 months after the initial dose of vaccine.nnnRESULTSnSeroprotection rates for subjects receiving the 20-micrograms dose of vaccine were slightly, but not significantly, greater than for subjects receiving the 10-micrograms dose, at each time point. However, at 3 months, males receiving the higher dose had significantly higher seroprotection rates than males receiving the lower dose: 63% versus 37% (p < 0.001). At 8 months, geometric mean titers for the group receiving Engerix-B 20 micrograms were significantly greater than that for the group receiving Recombivax HB 10 micrograms: 840 mIU/mL versus 340 mIU/mL (p = 0.001).nnnCONCLUSIONSnImmunization with the 20-micrograms dose of recombinant hepatitis B virus vaccine appeared to result in more rapid development of seroprotective anti-HBs titers in older men and in higher titers of anti-HBs at the completion of vaccination when compared to the 10-micrograms dose. The latter data suggest that the 20-micrograms dose may result in a longer duration of seroprotective anti-HBs titers.


The American Journal of Gastroenterology | 1998

Clinical aspects of upper gastrointestinal bleeding associated with the use of nonsteroidal antiinflammatory drugs.

András Laszlo; Judith P. Kelly; David E Kaufman; Jane E. Sheehan; György Rétsági; Bengt-Erik Wiholm; Raymond S. Koff; Anders Sundström; Samuel Shapiro

Objective:The aim of this study was to compare the clinical features of major upper gastrointestinal bleeding among patients exposed to nonsteroidal antiinflammatory drugs (NSAID) and those not taking these drugs.Methods:Using data from a multicenter international case-control study designed to evaluate the role of drugs in the etiology of major upper gastrointestinal bleeding (UGIB), patients with a confirmed first episode of major UGIB were divided into two groups: those exposed to NSAIDs during the week before the onset of bleeding, and those not exposed. The groups were compared according to age and sex, clinical appearance and site of the bleeding, preceding symptoms, and requirement for transfusion and acute surgery.Results:The median age was significantly higher and the proportion of women was slightly higher among the NSAID users. There was no significant difference between users and nonusers according to the clinical presentation, the site of the bleeding, or the frequency of preceding symptoms. Forty percent in each group had no symptoms before the onset of bleeding. Slightly more NSAID users received blood transfusions, although the same median amount of blood per transfusion was given in both groups. There was no difference in the frequency of surgical intervention.Conclusions:There are no important differences in the clinical presentation of major UGIB according to whether or not an individual is an NSAID user. An important finding is the frequent absence of preceding symptoms in patients with major UGIB, regardless of NSAID use.


Cancer Letters | 1993

α-Fetoprotein glycosylation is abnormal in some hepatocellular carcinomas, including white patients with a normal α-fetoprotein concentration

Andrew B. Ajdukiewicz; Philip C. Kelleher; Edward L. Krawitt; Carol P. Walters; Pamela B. Mason; Raymond S. Koff; Luc Bélanger

Abstract Lectin-affinity analyses with Lens culinaris agglutinin (LCA) and other lectins have demonstrated that the glycosylation of α-fetoprotein (AFP) secreted by hepatocellular carcinomas (HCC) is frequently altered when the serum AFP concentration is increased. To determine if AFP LCA-binding properties are altered in patients with HCC whose serum AFP concentration is normal, the percentage of LCA-binding AFP in serum from white newborns, white normal adults, white patients with chronic hepatitis and hereditary tyrosinemia and white and black patients with HCC were determined. The serum LCA-binding AFP fraction was low in newborns (1–4%) and normal adults (1–8%). There was a significant increase in LCA-binding AFP in patients with chronic hepatitis (10–24%) and hereditary tyrosinemia (5–35%). The AFP LCA-binding fraction was clearly abnormal (greater than 40%) in three of the white patients with an HCC and a normal serum AFP concentration, and the range of values (10–63%) in these HCC patients was similar to that seen in both white and black patients with HCC accompanied by increased AFP concentrations.


Hepatology | 1998

Safety and immunogenicity of hepatitis A vaccine in patients with chronic liver disease

Emmet B. Keeffe; Sten Iwarson; Brian J. McMahon; Karen L. Lindsay; Raymond S. Koff; Michael P. Manns; Renate Baumgarten; Manfred Wiese; Marc Fourneau; Assad Safary; Ralf Clemens; David S. Krause


The American Journal of Gastroenterology | 1995

Alcohol consumption and the risk of major upper gastrointestinal bleeding

Judith P. Kelly; David W Kaufman; Raymond S. Koff; András Laszlo; Bengt-Erik Wiholm; Samuel Shapiro


Hepatology | 1999

A phase I/II study of recombinant human interleukin‐12 in patients with chronic hepatitis C

Stefan Zeuzem; Uwe Hopf; Vicente Carreño; M. Diago; Mitchell L. Shiffman; Stefan Grüne; Francis J. Dudley; Ashok Rakhit; Karen Rittweger; Sing Hiem Yap; Raymond S. Koff; Howard C. Thomas

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Stefan Zeuzem

Goethe University Frankfurt

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