Biomedical subjects

E F Hensen

Publications and source records attributed to E F Hensen.

8 recordsLinked to original sources

PubMed2004

Hernia surgery changes in the Amsterdam region 1994-2001: decrease in operations for recurrent hernia.

Inguinal hernia (IH) surgery has changed substantially in the past decade. Conventional (nonmesh) techniques have largely given way to prostheses. This study's aim was to analyse whether changes in technique used for IH repair influenced the operation rate for recurrence. A retrospective study was performed on all adult males who had undergone IH surgery in the Amsterdam region during the calendar years of 1994, 1996, 1999, and 2001. Data were obtained for 3,649 subjects and included patient demographics, hernia type, and surgical technique. We observed a decrease in the use of conventional techniques and a significant increase (P<0.05) in the use of prosthetic materials. The number of operations performed for recurrent hernia decreased from 19.5% (216/1,108) in 1994, to 16.8% 197/1,170) in 1996, to 14.0% (152/1,088) in 1999, and to 14.1% (40/283) in 2001. When comparing 1999 and 2001 with 1994, there was a significant decrease in operations performed for recurrent hernia (P=0.005). There was also a significant increase in supervision of the surgical resident by a surgeon.

Adolescent↗

PubMed2000

Development of antibodies against tetravalent meningococcal polysaccharides in revaccinated complement-deficient patients.

Individuals deficient in C3 or a late complement component are susceptible to recurrent meningococcal infections. Since they experience meningococcal episodes mostly with uncommon meningococcal serogroups, vaccination with a tetravalent vaccine containing A, C, Y and W135 polysaccharides has been suggested. We vaccinated a cohort of two C3 and 17 late complement component-deficient (LCCD) patients, revaccinated them 7 years later and investigated the development of their IgG antibodies to the capsular polysaccharides of the meningococcal vaccine. Seven years after the first vaccination levels of IgG antibodies declined compared with the levels present at 6 months after the first vaccination, but were still at least four times higher than before vaccination. Levels of antibodies to Y polysaccharide in serum of complement-deficient patients were rather low but they did not differ significantly from those in serum of healthy non-related controls (P = 0.07). Three months after the second vaccination IgG antibodies against all polysaccharides increased, exceeding those measured at 6 months after the first vaccination. In the 8 years of observation after the first vaccination two new meningococcal infections with strains related to the vaccine (serogroup Y strains) occurred in two patients, 3.5 and 5 years after the first vaccination. Our findings show that high IgG antibody levels against the tetravalent meningococcal polysaccharide vaccine were reached after revaccination of two C3 and 17 LCCD individuals 7 years after the first vaccination. Whether revaccination should be required within a period shorter than 7 years is discussed, since two vaccinees developed meningococcal disease to vaccine serogroup Y.

Adolescent↗

PubMed1999

[Laser-assisted 13C-urea breath test; a new noninvasive detection method for Helicobacter pylori infection].

OBJECTIVE: To assess the laser assisted ratio analyser (LARA) system for detection of Helicobacter pylori infection in breath samples. DESIGN: Descriptive. METHOD: Diagnostic gastroscopy with biopsies for histopathology and culture was performed in consecutive dyspeptic patients in the Department of Gastroenterology of the Academic Medical Centre of Amsterdam in January-May 1996. Subsequently, a LARA test was carried out, which measures the degradation by H. pylori of 13C urea using the ratio of 12CO2/13CO2 in the exhaled air. The combination of the results of the examination of gastric biopsies was regarded as the golden standard for the demonstration of H. pylori infection. After this comparison, the cut-off level above which the LARA system demonstrated H. pylori infection was established in the basis of a receiver operator characteristics (ROC) analysis. An area was defined round this value within which the results were inconclusive and outside of which the reliability increased. RESULTS: 208 patients were included in the study; the data of nine of them could not be analysed (CO2 level in the exhaled air too low: 8; withdrawal: 1). The remaining 199 patients were 105 males and 94 females with a mean age of 48 years (range 19-75). Ninety-three of them (47%) were H. pylori positive according to the golden standard. With the breath analysis infection was detected in 86 of them, while in 97 patients breath analysis was correctly negative; it was false-negative in four, false-positive in three and unreliable in nine patients. The sensitivity was 96%, the specificity 97%. The positive and negative predictive values were 97% and 96%, respectively.

Adult↗

PubMed1999

A systematic review of Helicobacter pylori eradication therapy--the impact of antimicrobial resistance on eradication rates.

BACKGROUND: We systematically reviewed all available data in the literature to determine the overall eradication rates of currently advised Helicobacter pylori eradication regimens and to resolve conflicting evidence on the impact of antimicrobial resistance on the eradication rates. METHODS: A comprehensive search of all published trials on H. pylori eradication therapy was carried out via an electronic database search, hand-searching and checking reference lists of pharmaceutical companies and other reviews. Full papers and abstracts in the English language which study currently advised eradication regimes were included. RESULTS: 770 study-arms were analysed. Mean eradication rates for bismuth based triple, proton pump inhibitor triple, quadruple and ranitidine bismuth citrate combination therapies vary from 65 to 92%. In case of nitroimidazole resistance, a drop in efficacy of up to 50% was found for bismuth-based triple and proton pump inhibitor-based triple therapies. For quadruple therapy, a significant difference in efficacy was found in the equal-effects analysis; however, this could not be confirmed in the random-effects analysis. In case of clarithromycin resistance, a mean drop in efficacy of 56% was found for one- and two-week clarithromycin containing proton pump inhibitor-triple therapies and of 58% for two-week ranitidine bismuth citrate combined with clarithromycin therapies. For ranitidine bismuth citrate combined with clarithromycin and nitroimidazole, no difference in efficacy was found in case of nitroimidazole or clarithromycin resistance, but data are still scarce. CONCLUSIONS: The cure rate with most regimens dropped significantly, in case of nitroimidazole-resistant strains, compared to nitroimidazole-susceptible strains. In case of clarithromycin resistance, the efficacy of most regimens is also decreased; however, data are still scarce. These data should allow physicians to make a better choice of an appropriate therapy for their patients.

Anti-Bacterial Agents↗

PubMed1999

Randomized trial of omeprazole and clarithromycin combined with either metronidazole or amoxycillin in patients with metronidazole-resistant or -susceptible Helicobacter pylori strains.

BACKGROUND: The impact of metronidazole resistance on the efficacy of proton pump inhibitor based triple therapies remains unclear. AIM: To study whether metronidazole resistance affects Helicobacter pylori eradication rates in patients treated for 1 week with either omeprazole 20 mg b.d., metronidazole 400 mg b.d. and clarithromycin 250 mg b.d. (OMC), or omeprazole 20 mg b.d., amoxycillin 1000 mg b.d. and clarithromycin 500 mg b.d. (OAC). METHODS: A randomized, single blind, single centre study with parallel groups was conducted. H. pylori positive patients were enrolled in a metronidazole-resistant (MR; MIC > 8 microgram/mL) or a metronidazole-susceptible group (MS; MIC < 4 microgram/mL), as determined by E-test. Within the strata patients were randomized to either OAC or OMC. RESULTS: One hundred and twenty-two patients were included. The per protocol cure rate for OAC was 52 out of 57 (91%) (MS 23 out of 26 (89%); MR 29 out of 31 (94%)) and for OMC 46 out of 55 (84%) (MS 19 out of 22 (86%); MR 27 out of 33 (82%)). CONCLUSIONS: One-week OAC and OMC are effective therapies. OAC and OMC were equally effective in patients with metronidazole-susceptible strains of H. pylori. Using the OMC regimen, neither equality nor significant differences in treatment outcome could be shown between patients with metronidazole-resistant or -susceptible strains of H. pylori.

Adolescent↗

PubMed1999

Helicobacter pylori eradication therapy in The Netherlands.

BACKGROUND: Helicobacter pylori cure rates vary in different geographical regions because of differences in hosts as well as in H. pylori strains. OBJECTIVE: To review systematically all available data in the literature to determine H. pylori eradication rates in The Netherlands. METHODS: A search of all published trials on H. pylori eradication therapy performed in The Netherlands was conducted via electronic database search, hand-searching of abstracts from scientific meetings and checking reference lists of pharmaceutical companies. Full papers and abstracts were included. Data on anti-H. pylori therapies were pooled based on duration and combination of drugs. Only triple and quadruple eradication regimens were studied. Dual therapies were excluded, except for ranitidine bismuth citrate-based dual therapies. RESULTS: We analysed 38 study arms, involving 2197 patients. Twenty different pooled regimens were studied with a mean intention-to-treat eradication rate of 83% (range 35-96%). There were no significant differences in the percentage of patients that stopped treatment due to adverse events between the groups. In these pooled regimens only bismuth combined with tetracycline and metronidazole for 1 or 2 weeks was significantly lower in efficacy in metronidazole-resistant strains than in metronidazole-sensitive strains. The prevalence of metronidazole-resistant strains in The Netherlands showed large regional differences (7-50%). CONCLUSIONS: A therapy should be tested in a defined population before becoming standard. Several eradication regimens studied in The Netherlands yield acceptable cure rates of 80% or more on an intention-to-treat basis. We advise taking the local prevalence of metronidazole resistance into account when choosing a first-line eradication regimen.

Antacids↗

PubMed1997

Meropenem susceptibility of Neisseria meningitidis and Streptococcus pneumoniae from meningitis patients in The Netherlands.

In-vitro susceptibility of 299 Neisseria meningitidis and 157 Streptococcus pneumoniae strains from meningitis patients in The Netherlands in 1993 and 1994 to meropenem was determined using the Etest. Susceptibility to penicillin, ceftriaxone, and chloramphenicol was also determined. Rifampicin susceptibility was additionally tested for N. meningitidis. Of the meningococci, 4.3% were of intermediate resistance to penicillin and 0.3% were resistant to rifampicin. One pneumococcal isolate (0.6%) was of intermediate resistance to penicillin. All strains were susceptible to meropenem. We conclude that meropenem is in vitro highly active against N. meningitidis and S. pneumoniae.

Anti-Bacterial Agents↗

PubMed1996

Antimicrobial susceptibility of Haemophilus influenzae, Neisseria meningitidis and Streptococcus pneumoniae isolates causing meningitis in The Netherlands, 1993-1994.

The increasing antimicrobial resistance among pathogens frequently isolated from patients with bacterial meningitis formed the rationale to perform a surveillance study to determine the prevalence of resistance in The Netherlands. Haemophilus influenzae strains (n = 316) isolated from cerebrospinal fluid (CSF), 1125 meningococcal strains isolated from blood or CSF and 398 pneumococcal strains isolated from CSF in 1993 and 1994 were tested by the Etest for susceptibility to commonly prescribed antibiotics for the treatment of community-acquired meningitis. In H. influenzae strains ampicillin-resistance occurred in 7.0%, resistance to chloramphenicol in 2.2%, and resistance to both antibiotics in 0.9%. The prevalence of intermediate penicillin-resistance in meningococci was 3.3%. Resistance to rifampicin was rarely found (0.1%). Intermediate penicillin-resistance in pneumococci was found in only 0.5% of isolates. All 1839 isolates were susceptible to ceftriaxone. Based on these results, we conclude that empirical therapy of childhood community-acquired bacterial meningitis with amoxycillin and chloramphenicol is no longer justified in children who have not been vaccinated against H. influenzae type b. In vaccinated or older children and adults, amoxycillin is a rational choice for empirical treatment of meningitis. The prophylactic use of rifampicin in contacts of patients with meningococcal disease is still applicable.

Adolescent↗