Standardized reprocessing of reusable colonoscopy biopsy forceps is effective: results of a German multicenter study.

BACKGROUND AND STUDY AIMS: National and international guidelines recommend that a standardized protocol consisting of cleaning, ultrasound cleaning, and sterilization should be used for the reprocessing of endoscopic accessories in order to reduce the risk of transmission of microorganisms. This German multicenter study investigated the efficacy of standardized reprocessing of reusable biopsy forceps used during colonoscopy. MATERIALS AND METHODS: Ten endoscopy centers (eight hospitals and two private practices) used 330 biopsy forceps during routine colonoscopy. The forceps were used once, five times, or 20 times for colonoscopy, based on a randomization plan. The reprocessing protocol consisted of manual cleaning with an enzymatic agent, ultrasound cleaning with an enzymatic agent (30 min, 40 degrees C, 47 Hz), neutralization, drying, and sterilization (5 min, 134 degrees C). Aldehydes were not used, and the protocol did not include a disinfection step. The biopsy forceps were sent to three microbiological institutes, based on a randomization plan, to have them tested for the presence of organisms, including identification of bacteria. RESULTS: A total of 318 of the 330 forceps were evaluable; 314 forceps (98.74 %) were sterile after use once, five times, or 20 times. Four forceps were contaminated with Staphylococcus epidermidis (n = 2), Bacillus licheniformis (n = 1) and Corynebacterium aquaticum (n = 2). All of 25 forceps were sterile after being used 20 times. CONCLUSION: Colonoscopy biopsy forceps can be reliably reprocessed following this standardized protocol, even without aldehydes.

Controlled balloon inflation reduces long-term restenosis after percutaneous transluminal coronary angioplasty.

PURPOSE: The trauma induced by balloon angioplasty has an impact on the outcome of coronary interventions, such as stent procedures. However, balloon inflation for PTCA is not yet standardized even though procedural and long-term outcomes might be affected. METHODS: During routine PTCA, a total of 454 patients [mean age, 60.9 +/- 9.0 years; 162 (35.7%) with 1-vessel disease; 159 (35%) with 2-vessel disease; 133 (29.3%) with 3-vessel disease] were allotted to computer-assisted dilatation (CAPS) with a pressure slope of 0.2 bar/s (CAPS 0.2; n = 149 patients), 1.0 bar/s (CAPS 1.0; n = 154 patients) or to standard inflation with a hand-driven pump (n = 151 patients). Angiographic follow-up rates after 4.1 +/- 3.2 months were 88.1% for the hand-driven pump, 94% for CAPS 0.2 and 87.7% for CAPS 1.0. RESULTS: Flow reducing (1.3-2.0%) and non-flow reducing (12.6-14.9%) dissections were equally distributed among all groups as were major adverse cardiac events (2.6-4.0%). The stent rate was 1.3% with the hand-driven pump, 0.7% with CAPS 0.2 and 1.3% with CAPS 1.0. Angiographic restenosis rate was 48.9% with the hand-driven pump, 44.3% with CAPS 0.2 and 32.6% with CAPS 1.0. (hand-driven pump versus CAPS 1.0, p < 0.007; CAPS 0.2 versus CAPS 1.0, p < 0.049). CONCLUSIONS: The pressure slope during balloon inflation in PTCA has a significant impact on restenosis. The impact on stent procedures has yet to be determined.

Comparison of image compression viability for lossy and lossless JPEG and Wavelet data reduction in coronary angiography.

BACKGROUND: Lossless or lossy compression of coronary angiogram data can reduce the enormous amounts of data generated by coronary angiographic imaging. The recent International Study of Angiographic Data Compression (ISAC) assessed the clinical viability of lossy Joint Photographic Expert Group (JPEG) compression but was unable to resolve two related questions: (A) the performance of lossless modes of compression in coronary angiography and (B) the performance of newer lossy wavelet algorithms. This present study seeks to supply some of this information. METHODS: The performance of several lossless image compression methods was measured in the same set of images as used in the ISAC study. For the assessment of the relative image quality of lossy JPEG and wavelet compression, the observers ranked the perceived image quality of computer-generated coronary angiograms compressed with wavelet compression relative to the same images with JPEG compression. This ranking allowed the matching of compression ratios for wavelet compression with the clinically viable compression ratios for the JPEG method as obtained in the ISAC study. RESULTS: The best lossless compression scheme (LOCO-I) offered a mean compression ratio (CR) of 3.80:1. The quality of images compressed with the lossy wavelet-based method at CR = 10:1 and 20:1 was comparable to JPEG compression at CR = 6:1 and 10:1, respectively. CONCLUSION: The study has shown that lossless compression can exceed the CR of 2:1 usually quoted. For lossy compression, the range of clinically viable compression ratios can probably be extended by 50 to 100% when applying wavelet compression algorithms as compared to JPEG compression. These results can motivate a larger clinical study.

Impact of viral and bacterial infectious burden on long-term prognosis in patients with coronary artery disease.

BACKGROUND: The number of infectious pathogens to which an individual has been exposed (infectious burden) may correlate with coronary artery disease (CAD). In a prospective study, we evaluated the effect of 8 pathogens and the aggregate pathogen burden on the risk for future fatal cardiac events among patients with angiographically documented CAD. Methods and Results-In 1018 patients, IgG or IgA antibodies to herpes simplex virus types 1 and 2, cytomegalovirus, Epstein-Barr virus, Haemophilus influenzae, Chlamydia pneumoniae, Mycoplasma pneumoniae, and Helicobacter pylori were determined. Moreover, highly sensitive C-reactive protein was measured. Follow-up information on cardiovascular events was obtained (mean 3.1 years, maximum 4.3 years). Seropositivities to Epstein-Barr virus (P=0.001), H pylori (P=0.002), and herpes simplex virus type 2 (P=0.045) were independently associated with the future risk of cardiovascular death. An increasing number for pathogen burden was significantly predictive of the long-term prognosis (P<0.0001). Infectious burden divided into 0 to 3, 4 or 5, and 6 to 8 seropositivities was associated with an increasing mortality of 3.7%, 7.2%, and 12.6%, respectively. Patients seropositive to >5 pathogens compared with those seropositive to <4 pathogens had a 5.1 (1.4 to 18.3) higher risk of future cardiac death. This result was mainly driven by the pathogen burden of seropositivities to Herpesviridae (P<0.0001). The prognostic impact of total or viral pathogen burden was independent of the C-reactive protein level. CONCLUSIONS: These results support the hypothesis that the number of infectious pathogens to which an individual has been exposed independently contributes to the long-term prognosis in patients with documented CAD.

Angiographic analysis of immediate and long-term results of PTCR vs. PTCA in complex lesions (COBRA study).

We conducted a prospective, randomized trial to compare immediate and long-term effects of percutaneous transluminal coronary angioplasty (PTCA) and high-frequency rotational atherectomy (PTCR) in patients with angiographically predefined complex coronary artery lesions (AHA type B2 and C). The relation of lesion characteristics to procedural results is reported in this angiographic analysis. Patients were randomly assigned to balloon angioplasty (n = 250 patients) or rotational atherectomy (n = 252 patients). Quantitative coronary angiography could be performed in 447 patients to evaluate immediate results and in 293 patients with a 6-month angiographic follow-up. Procedural success was comparable in the PTCR and in the PTCA group (80% vs. 76%, P = 0.260). The need for stent implantation due to a residual stenosis >50% or a bail-out situation was significantly higher in the PTCA group (9.7% vs. 2.0%, P = 0.001). In both treatment groups, diameter stenosis was effectively reduced and MLD increased. The acute gain did not differ between the two groups. At 6-month control, the restenosis rate was comparable in the PTCR and in the PTCA group (37% vs. 35%, P = 0.658), whereas diameter stenosis was significantly more severe in the PTCR group than in the PTCA group (52% vs. 46%, P = 0.039) and, correspondingly, the MLD was significantly smaller in the PTCR group (1.29 mm vs. 1.44 mm, P = 0.031). Late loss was about the same in both groups, however, net gain and net gain index were significantly higher in the PTCA group (0.82 mm vs. 0.64 mm, P = 0.008; and 31% vs. 24%, P = 0.009). Analysis of procedural results for various lesion characteristics revealed no significant difference between treatment groups. In this randomized trial, complex coronary artery lesions were treated with comparable results for angiographic and procedural success and the restenosis rate by both, PTCA and PTCR. Late loss, however, was significantly higher and net gain significantly smaller after PTCR. Stents, although infrequently used, had a relevant impact on immediate PTCA results but not on late results. Cathet Cardiovasc Intervent 2001;53:359-367.

Cytomegalovirus infection with interleukin-6 response predicts cardiac mortality in patients with coronary artery disease.

BACKGROUND: Prospective data relating previous exposure to cytomegalovirus (CMV) to the risk of cardiac mortality are controversial. We investigated the effect of previous exposure to CMV infection on the risk of future cardiac disease-related death in relation to an underlying inflammatory response. METHODS AND RESULTS: coronary angiography was performed in 1134 subjects, and 989 patients with documented coronary artery disease were studied prospectively. CMV-IgG titers and interleukin (IL)-6 levels were measured before angiography. Increasing titers of CMV correlated with the elevation of IL-6 levels (P<0.001) after adjustment for possible confounders. All patients were followed up for a median of 3.1 years (maximum 4.3 years). During follow-up, 96 patients died, 70 of cardiac disease. Overall, CMV seropositivity was not related to cardiac mortality after adjustment for confounding variables (P=0.19). In contrast, in patients with elevated IL-6 levels (>/=11.9 pg/mL, median level), CMV seropositivity was independently associated with a 3.2-fold (95% CI 1.4 to 7.3, P=0.007) increase in risk of future cardiac death, whereas in individuals without IL-6 elevation, previous CMV infection had no effect on cardiac mortality. CONCLUSIONS: MV seropositivity in patients with an inflammatory response is independently associated with future cardiac mortality, whereas this association is lost in patients who do not demonstrate an inflammatory response. These data support the hypothesis that the atherosclerotic effects of CMV are mediated through an underlying inflammatory response.

Design issues and sample size when exposure measurement is inaccurate.

Measurement error often leads to biased estimates and incorrect tests in epidemiological studies. These problems can be corrected by design modifications which allow for refined statistical models, or in some situations by adjusted sample sizes to compensate a power reduction. The design options are mainly an additional replication or internal validation study. Sample size calculations for these designs are more complex, since usually there is no unique design solution to obtain a prespecified power. Thus, additionally to a power requirement, an optimal design should also fulfill the criteria of minimizing overall costs. In this review corresponding strategies and formulae are described and appraised.

Effect of the atrial blanking time on the detection of atrial fibrillation in dual chamber pacing.

Patients with paroxysmal atrial fibrillation (PAF) and dual chamber pacemakers frequently have short postventricular atrial blanking times and sensitive atrial sensing thresholds used to provide reliable detection and mode switching during AF. However, short atrial blanking times increase the risk of atrial sensing of ventricular far-field signals. We evaluated if the length of the atrial blanking time influences the detection of AF. The study included ten patients with a VDDR (n = 7) or DDDR system (n = 3), who presented with AF at 18 follow-up visits. Bipolar atrial sensing was programmed to the most sensitive value. Atrial blanking times were programmed from 100 to 200 ms in 25-ms steps in each patient. Using marker annotation, the following parameters were measured at ten consecutive ventricular beats: VAF = the interval between ventricular stimulus and first sensing of AF; AFS = the number of atrial-sensed events between two ventricular events; and XAF = the interpolated number of atrial-sensed events during atrial blanking time. The intervals between ventricular events and between atrial-sensed event markers showed no significant differences for the five blanking times tested. There was no significant influence of the atrial blanking time onto the measured parameters (least square means +/- standard error) with VAF between 281 +/- 12 and 300 +/- 12 ms (P = NS), AFs between 3.4 +/- 0.2 and 3.6 +/- 0.2 beats (P = NS) and XAF between 1.84 +/- 0.12 and 2.03 +/- 0.12 beats (P = NS). At ventricular rates < 100/min, the atrial sensing of AF in dual chamber pacemakers demonstrated no evidence for deterioration by an increase of the atrial blanking time from 100 to 200 ms. Thus, the risk of ventricular far-field sensing may be reduced without compromising atrial sensing.

Temperature-controlled high frequency ablation for creation of transmyocardial channels: in vivo validation of a novel method.

OBJECTIVE: We investigated the feasibility and short-term effects of a novel procedure to create intramyocardial channels by means of high frequency (HF) ablation in a rabbit in vivo model. METHODS: A flexible catheter ending in a cylindrical electrode (diameter 0.7 mm) with a sharpened tip was used for HF energy application following transmyocardial insertion. Power-controlled or energy-controlled energy applications were performed in 16 anesthetized rabbits after thoracotomy with a follow-up for 3 h. Assessment of myocardial channels and the necrotic zone was performed by morphometric quantification in serial sections. The ferret diameter was used to compare channel dimensions and the extent of necrosis. RESULTS: Thirty-nine power-controlled and 54 temperature-controlled HF applications were performed. The shape of identified channels was round in 71% and 69% had a lumen patency of > or =2/3 of the channel. Ferret diameter of the channels was 414 +/- 180 microm and of the necrotic zone 3,558 +/- 1,200 microm. In temperature-controlled applications, channel dimensions were strongly influenced by the maximum tissue temperature and the duration of energy delivery (T(max): p = 0.0006; duration: p = 0. 003). Channel and necrosis dimensions correlated better with biometric parameters in temperature-controlled compared with power-controlled applications. CONCLUSION: Mechanically created transmyocardial channels can be stabilized by HF heating of the surrounding tissue. A high percentage of these channels remain patent. The channel dimensions are closely correlated with maximum temperature and duration of energy delivery in a temperature-controlled application mode.

Are morphological or functional changes in the carotid artery wall associated with Chlamydia pneumoniae, Helicobacter pylori, cytomegalovirus, or herpes simplex virus infection?

BACKGROUND AND PURPOSE: Chronic infection with Chlamydia pneumoniae, Helicobacter pylori, cytomegalovirus (CMV), and herpes simplex virus (HSV) has been implicated in the pathogenesis of atherosclerosis. The carotid intima-media thickness (IMT) can be taken to indicate early atherosclerosis, the presence of a carotid stenosis is a marker of a manifest carotid atherosclerosis, and an increase in arterial stiffness is used as marker of structural and functional changes in an atherosclerotic vessel wall. METHODS: In 504 patients (75% men; mean age 62.9 [SD 10] years), we measured the IMT and the elastic pressure modulus (EP; n=445) of the common carotid artery and the prevalence of a internal or external carotid artery stenosis. Blood samples were taken, and antibodies against C pneumoniae, H pylori, CMV, and HSV types 1 and 2 were evaluated. Statistical evaluation was performed with regression procedures and multivariate logistic regression analyses. RESULTS: Seropositivity for C pneumoniae was an independent predictor for a combined end point of highest category of IMT and carotid artery stenosis (OR 1.8, 95% CI 1.1 to 3.1; adjusted) for IgG titers. Independently, CMV increased the risk for the combined end point (OR 1.7, 95% CI 1.1 to 2.8; adjusted) for IgG titers and for IgA titers (OR 2.3, 95% CI 1.1 to 4. 9; adjusted). We found a significant correlation between IgG antibodies against CMV and EP; HSV type 2 IgG titers were associated with IMT and carotid stenosis, but the latter results were no longer significant after adjustment. There was no association with H pylori or HSV type 1. CONCLUSIONS: We found a significant association of IgG antibodies against C pneumoniae and CMV with early and advanced carotid atherosclerosis. CMV was also correlated to functional changes of the carotid artery, but this could not be confirmed after adjustment.

Dose-adjusted thrombosis prophylaxis in trauma surgery according to levels of D-Dimer.

In 234 trauma surgery patients, thrombosis prophylaxis with Nadroparin-Calcium low-molecular-weight heparin (LMWH) was adjusted according to levels of D-Dimer. Basic prophylaxis was 2,850 IU per day. If D-Dimer concentrations rose above 2 mg/L after the fourth postoperative (p.o.) day, LMWH was administered twice a day. Color Doppler ultrasound was performed between the fifth and seventh p.o. days. Patients were divided into a high-risk (group 1: hip, femur, or knee replacement surgery, n=102) and a moderate-risk group (group 2: other surgery of the knee, tibia, fibula, or foot, n=132). Group 1 showed significantly higher D-Dimer levels than group 2 (p<0.001). Measurement of D-Dimer on days 2 and 4 p.o. showed a sensitivity of 100% and a specificity of 72.8% in identifying patients at risk (i.e., D-Dimer>2 mg/L after day 4 p.o.). The overall deep vein thrombosis (DVT) rate in group 1 was 3.9%, and the rate of proximal DVT was 1.96%. In group 2, one distal DVT (0.8%) occurred. The results show that D-Dimer is a useful marker to monitor p.o. coagulation activation and to manage LMWH prophylaxis in trauma surgery patients.

American College of Cardiology/European Society of Cardiology International Study of Angiographic Data Compression Phase III: measurement of image quality differences at varying levels of data compression.

OBJECTIVES: We sought to investigate up to which level of Joint Photographic Experts Group JPEG) data compression the perceived image quality and the detection of diagnostic features remain equivalent to the quality and detectability found in uncompressed coronary angiograms. BACKGROUND: Digital coronary angiograms represent an enormous amount of data and therefore require costly computerized communication and archiving systems. Earlier studies on the viability of medical image compression were not fully conclusive. METHODS: Twenty-one raters evaluated sets of 91 cine runs. Uncompressed and compressed versions of the images were presented side by side on one monitor, and image quality differences were assessed on a scale featuring six scores. In addition, the raters had to detect pre-defined clinical features. Compression ratios (CR) were 6:1, 10:1 and 16:1. Statistical evaluation was based on descriptive statistics and on the equivalence t-test. RESULTS: At the lowest CR (CR 6:1), there was already a small (15%) increase in assigning the aesthetic quality score indicating "quality difference is barely discernible-the images are equivalent." At CR 10:1 and CR 16:1, close to 10% and 55%, respectively, of the compressed images were rated to be "clearly degraded, but still adequate for clinical use" or worse. Concerning diagnostic features, at CR 10:1 and CR 16:1 the error rate was 9.6% and 13.1%, respectively, compared with 9% for the baseline error rate in uncompressed images. CONCLUSIONS: Compression at CR 6:1 provides equivalence with the original cine runs. If CR 16:1 were used, one would have to tolerate a significant increase in the diagnostic error rate over the baseline error rate. At CR 10:1, intermediate results were obtained.

American College of Cardiology/ European Society of Cardiology international study of angiographic data compression phase III. Measurement Of image quality differences at varying levels of data compression.

OBJECTIVES: We sought to investigate up to which level of Joint Photographic Experts Group (JPEG) data compression the perceived image quality and the detection of diagnostic features remain equivalent to the quality and detectability found in uncompressed coronary angiograms. BACKGROUND: Digital coronary angiograms represent an enormous amount of data and therefore require costly computerized communication and archiving systems. Earlier studies on the viability of medical image compression were not fully conclusive. METHODS: Twenty-one raters evaluated sets of 91 cine runs. Uncompressed and compressed versions of the images were presented side by side on one monitor, and image quality differences were assessed on a scale featuring six scores. In addition, the raters had to detect pre-defined clinical features. Compression ratios (CR) were 6:1, 10:1 and 16:1. Statistical evaluation was based on descriptive statistics and on the equivalence t -test. Results At the lowest CR (CR 6:1), there was already a small (15%) increase in assigning the aesthetic quality score indicating "quality difference is barely discernible-the images are equivalent.' At CR 10:1 and CR 16:1, close to 10% and 55%, respectively, of the compressed images were rated to be "clearly degraded, but still adequate for clinical use' or worse. Concerning diagnostic features, at CR 10:1 and CR 16:1 the error rate was 9.6% and 13.1%, respectively, compared with 9% for the baseline error rate in uncompressed images. CONCLUSIONS: Compression at CR 6:1 provides equivalence with the original cine runs. If CR 16:1 were used, one would have to tolerate a significant increase in the diagnostic error rate over the baseline error rate. At CR 10:1, intermediate results were obtained.

Tenascin expression patterns and cells of monocyte lineage: relationship in human gliomas.

Stromal extracellular matrix (ECM) components are thought to play an important role in regulating invasion of human gliomas. Macrophages and microglial cells may heavily influence the integrity of the extracellular compartment of gliomas, and the affected ECM may play a key role in regulating migratory activity of both tumor cells and macrophages/microglia. The aim of this investigation was to study immunohistochemically the expression patterns of four ECM components: fibronectin, laminin, collagen IV, and tenascin (TN) in human gliomas, with special attention to TN. Our main goal was to study the possible correlation between TN expression and macrophagic/microglial infiltration in gliomas. Altogether, 90 gliomas were studied. Tumors included 46 glioblastomas, 19 anaplastic gliomas, 22 low grade gliomas, and 3 pilocytic astrocytomas. Vascular TN prevailed in perinecrotic areas of glioblastomas, whereas interstitial TN was more often expressed distant from necrosis and in the ECM of anaplastic and low grade gliomas. Double staining with CD68 and anti-TN antibodies showed that macrophagic/microglial density was significantly higher in TN-positive areas of most of the glioblastomas and anaplastic gliomas, whereas microglial percentage from total number of CD68-positive cells was in most of the cases significantly higher in TN-negative areas. In addition, we saw a morphologically spatial correlation between higher densities of macrophagic/microglial infiltration and TN expression in perinecrotic areas in glioblastomas. Attachment of macrophages to TN-positive basement membrane zones of newly formed stromal blood vessels was evident. On the basis of our results, we conclude that TN may play a crucial role in regulating trafficking of cells of monocyte lineage in human gliomas.

Extremely low frequency magnetic fields in residences in Germany. Distribution of measurements, comparison of two methods for assessing exposure, and predictors for the occurrence of magnetic fields above background level.

We examined the results of 1,835 magnetic field measurements in German residences conducted between November 1997 and September 1999. The measurements were part of an epidemiological study on the relationship between magnetic fields and childhood leukemia. We performed a fixed-location measurement of the magnetic field at 50 Hz and 16 2/3 Hz (frequency of the German railway system) over 24 h in the child's bedroom in the residence of each study participant. In addition, we conducted a second 24 h-measurement in the living room at 50 Hz, and spot measurements while walking through all rooms of the respective dwelling. Median 50 Hz magnetic fields above 0.2 muT were found to be infrequent in Germany (only 1.4% of all residences). Fields produced by high-voltage power lines (123-420 kV) were lower than expected: the median magnetic field was above 0.2 muT in only 8 (32.0%) of 25 residences located 50 m or closer to a high-voltage power line indicating that power lines in Germany are usually run well below the maximum power load. We found that magnetic fields were correlated with the type of residence and higher magnetic fields were measured in apartment buildings. There was also some evidence for a positive correlation between magnetic fields and traffic density and an inverse association between magnetic fields and family net income. The 24 h-magnetic field measurements correlated well with the spot measurements (r>0.7). However, when dichotomized with a cut-off point of 0.2 muT, there was only a poor agreement between the two measurement methods. A loss of the strength of the association after categorization was also observed when comparing the arithmetic mean and median of the same 24 h-measurement. In summary, these analyses give a valuable overview of magnetic field distributions in German residences.

Stress reduction in resin-based composites cured with a two-step light-curing unit.

PURPOSE: To examine the stress reduction of different resin-based composites, cured with a two-step polymerization unit (Elipar Highlight) by means of a photoelastic investigation. MATERIALS AND METHODS: For each material (Pertac II, Tetric Ceram, Charisma F, Solitaire, Dyract, Dyract AP, Definite), a minimum of 10 resin samples, embedded in acrylic-glass plates, were polymerized using a standard polymerization process of 700 mW/cm for 40 s. Another 10 samples were polymerized with a light output of 150 mW/cm2 for 10 s and then with a light output of 700 mW/cm2 for 30 s. RESULTS: For Pertac II the reduction of polymerization stress in the two-step-mode was 15.5%, for Tetric Ceram 14.5%, for Solitaire 8.1%, for Dyract AP 6.5% and for Definite 4.7%. These differences in polymerization stress between the standard and two-step-polymerization mode were statistically significant (P < 0.01, Wilcoxon test). No statistically significant differences in polymerization stress could be found for Charisma F and Dyract.

Short Barrett: prevalence and risk factors.

BACKGROUND: The incidence of adenocarcinoma at the gastro-oesophageal junction is on the increase. These carcinomas are usually diagnosed too late and thus have a poor prognosis. Only early diagnosis can improve the situation. Classical Barrett oesophagus (length, >3 cm) is a known precancerous condition. There is also specialized columnar epithelium (SCE) in the grossly unremarkable gastro-oesophageal transitional zone (short Barrett). METHODS: To determine the frequency of SCE, 370 patients were investigated by gastroscopy (OGD) consecutively between September 1995 and February 1996. RESULTS: Classical Barrett oesophagus was found to have an incidence of 4.6%. In contrast, microscopic evidence of SCE was observed in 13.6% of the cases. Patients with short Barrett presented with reflux symptoms (odds ratio (OR), 4.7), irregular zona serrata ('tongues') in the cardia (OR, 2.8), and reflux oesophagitis significantly more frequently. Patients with reflux symptoms and concomitant 'tongues', however, had an OR of 13.16. Careful history-taking, together with a subtle histologic work-up of the gastro-oesophageal transitional zone can improve the rate of detecting patients with short Barrett. CONCLUSION: Patients with reflux symptoms and irregular zona serrata should be selectively biopsied at the gastro-oesophageal junction, even when the latter presents a grossly normal appearance, with the aim of detecting patients at risk of developing a Barrett carcinoma.

A comparison of 3H-cocaine binding on melanin granules and human hair in vitro.

The in vitro experiments on the interaction of 3H-cocaine and melanin from Sepia officinalis confirmed the existence of drug binding sites on melanin granules. The results suggested that the binding of 3H-cocaine to melanin could be analyzed by assuming that the binding to the surface of pigment granules is analogous to the adsorption of a drug on a solid and follows Langmuir adsorption isotherm type I. Scatchard analysis indicated heterogeneity of binding sites. Structural and chemical alterations caused by isolation of the melanoproteins, which are heterogeneous in nature and show different physico-chemical properties, are considered to be most crucial. The studies on hair samples confirmed that melanin-drug interaction occur on the surface of melanin granules. These seem to be of minor importance compared to the drug-melanoprotein loading during melanogenesis for the observed influence of pigmentation on the drug content of hair fibers. From the results it was concluded that in vitro studies on melanin provide limited information and even drug-soaked hair must be regarded as inappropriate for the study of melanin-drug-binding in hair.