Characteristics of human monocytes cultured in the Teflon culture bag.

Blood monocytes from healthy volunteers were isolated by Ficoll-Isopaque centrifugation and cultured (together with lymphocytes) in medium 199 with 20% heat-inactivated newborn calf serum in a Teflon culture bag. Quantifiable data on survival showed that up to 21 days of culture, approximately 40% of the initial number of monocytes were still viable. Such cultures could be maintained for more than 8 weeks without refeeding. The monocytes exhibited the morphology of macrophages after 5-7 days of culture, and increased in size during culture. Less than 1% of the cells became giant cells even after long culture periods. Almost all cultured monocytes were positive for alpha-naphthyl butyrate esterase, whereas the peroxidase-positive granules disappeared during the first week of culture. After long culture times increasing amounts of lysozyme and angiotensin-converting enzyme were detected in the culture supernatants. Phagocytosis of staphylococci did not decrease appreciably during culture, and the same holds for intracellular killing of these bacteria. Chemotactic activity decreased during culture, whereas the chemokinetic response of the monocytes persisted.     

The importance of vacA, cagA, and iceA genotypes of Helicobacter pylori infection in peptic ulcer disease and gastroesophageal reflux disease

OBJECTIVE: To study the relationship between the presence of H. pylori virulence factors and clinical outcome in H. pylori infected patients. METHODS: DNA was isolated from an antral biopsy sample and vacA, cagA, and iceA genotype were determined by PCR and a reverse hybridization technique in 183 patients with culture-proven H. pylori infection: 51 with peptic ulcer disease (PUD), 62 with gastroesophageal reflux disease (GERD), and 70 with a normal endoscopy (gastritis only; GO). RESULTS: Forty-four samples (24%) showed more than one allelic variant in the vacA s- or in-region and/or both iceA1 and iceA2 genotypes, indicating multiple strain infection. These were excluded from statistical analysis. vacA s1 and cagA were significantly more common in PUD than in GERD and GO. Logistic regression analysis showed that GERD patients were more often infected with strains lacking both cagA and iceA than GO patients (OR = 0.36; CI = 0.15-0.89). Trend analysis showed that GERD patients were most often infected with less virulent strains (p < 0.002). CONCLUSION: Multiple strain infection is common. H. pylori strains possessing the vacA s1 genotype and/or cagA are associated with PUD. GERD patients, infected with H. pylori, mostly carry less virulent strains possessing neither cagA nor iceA1. Our findings support the hypothesis that virulent strains protect against the development of GERD.     

Cranial translation of the humeral head on radiographs in rotator cuff tear patients: the modified active abduction view

Cranial translation of the humeral head is related to massive rotator cuff tears; however, it may be unapparent in early-stage tears. The goal of this study was to investigate whether active abduction leads to increased active cranial humeral translation in early-stage tears. We assessed 20 consecutive patients (9 full-thickness supraspinatus tears, 11 posterosuperior tears) using the newly introduced modified active abduction view: acromiohumeral (AH) distance was measured on radiographs acquired during rest and active isometric abduction and adduction tasks with the arm alongside the body. Rest AH was 7.5 mm (SD = 1.53); during abduction and adduction, it decreased to 2.1 mm (95 % CI 1.28–3.01, p < 0.001) and 1.1 mm (95 % CI 0.46–1.65, p = 0.001), respectively. Cranial translation during abduction was more severe in shoulders with posterosuperior cuff tears (?AH = 3 mm, SD = 1.5) compared to supraspinatus tears (?AH = 1 mm, SD = 1.6), with a mean difference of 2 mm (95 % CI 0.64–3.58, p = 0.007). Both active isometric abduction and adduction leads to active cranial translation in cuff tear patients. Cranial translation is largest during active abduction. Furthermore, there is significant more cranial translation in posterosuperior cuff tear patients compared to supraspinatus cuff tear patients. Possibly, radiographs combined with active tasks offer new possibilities in diagnosing early-stage rotator cuff tears.     

Pretransplantation Donor–Recipient Pair Seroreactivity Against BK Polyomavirus Predicts Viremia and Nephropathy After Kidney Transplantation

Kidney transplant donors are not currently implicated in predicting BK polyomavirus (BKPyV) infection in kidney transplant recipients. It has been postulated, however, that BKPyV infection originates from the kidney allograft. Because BKPyV seroreactivity correlates with BKPyV replication and thus might mirror the infectious load, we investigated whether BKPyV seroreactivity of the donor predicts viremia and BKPyV‐associated nephropathy (BKPyVAN) in the recipient. In a retrospective cohort of 407 living kidney donor–recipient pairs, pretransplantation donor and recipient sera were tested for BKPyV IgG levels and correlated with the occurrence of recipient BKPyV viremia and BKPyVAN within 1 year after transplantation. Donor BKPyV IgG level was strongly associated with BKPyV viremia and BKPyVAN (p < 0.001), whereas recipient BKPyV seroreactivity showed a nonsignificant inverse trend. Pairing of high–BKPyV‐seroreactive donors with low‐seroreactive recipients resulted in a 10‐fold increased risk of BKPyV viremia (hazard ratio 10.1, 95% CI 3.5–29.0, p < 0.001). In multivariate analysis, donor BKPyV seroreactivity was the strongest pretransplantation factor associated with viremia (p < 0.001) and BKPyVAN (p = 0.007). The proportional relationship between donor BKPyV seroreactivity and recipient infection suggests that donor BKPyV seroreactivity reflects the infectious load of the kidney allograft and calls for the use of pretransplantation BKPyV serological testing of (potential) donors and recipients.     

Rapid diagnostic testing of methicillin-resistant Staphylococcus aureus carriage at different anatomical sites: costs and benefits of less extensive screening regimens

Multiple body site screening and pre-emptive isolation of patients at risk for methicillin-resistant Staphylococcus aureus (MRSA) carriage are considered essential for control of nosocomial spread. The relative importance of extranasal screening when using rapid diagnostic testing (RDT) is unknown. Using data from a multicentre study evaluating BD GeneOhm? MRSA PCR (IDI), Xpert MRSA (GeneXpert) and chromogenic agar, added to conventional cultures, we determined cost-effectiveness assuming isolation measures would have been based on RDT results of different hypothetical screening regimes. Costs per isolation day avoided were calculated for regimes with single or less extensive multiple site RDT, regimes without conventional back-up cultures and when PCR would have been performed with pooling of swabs. Among 1764 patients at risk, MRSA prevalence was 3.3% (n = 59). In all scenarios the negative predictive value is above 98.4%. With back-up cultures of all sites as a reference, the costs per isolation day avoided were £15.19, £30.83 and £45.37 with ‘nares only’ screening using chromogenic agar, IDI and GeneXpert, respectively, as compared with £19.95, £95.77 and £125.43 per isolation day avoided when all body sites had been screened. Without back-up cultures costs per isolation day avoided using chromogenic agar would range from £9.24 to £76.18 when costs per false-negative RDT range from £5000 up to £50 000; costs for molecular screening methods would be higher in all scenarios evaluated. In conclusion, in a low endemic setting chromogenic agar screening added to multiple site conventional cultures is the most cost-effective MRSA screening strategy.     

Dyspepsia management in primary care

BACKGROUND: Dyspepsia is common in western society. Prompt endoscopy is imperative in all patients with sinister symptoms or if symptoms first appear after the age of 50-55 years, but the optimal management of younger patients with uncomplicated dyspepsia is still open to debate. METHODS: The literature on the management of uncomplicated dyspepsia is reviewed and a personal view is presented. RESULTS: Strategies based on non-invasive detection of Helicobacter pylori are probably the most cost-effective. Currently (H. pylori prevalence 30%-40%), a 'test and treat' approach using a non-invasive test to detect H. pylori is likely to be the most efficient first step. If the patient is H. pylori-negative or if symptoms persist after successful H. pylori eradication, empirical treatment with an anti-secretory drug is justified. Endoscopy is reserved for those patients in whom this approach fails. If the prevalence of H. pylori decreases, the positive predictive value of any non-invasive H. pylori test will become too low. A 'test and scope' approach in which a positive test can be confirmed by two or more biopsy-based tests is then more appropriate. At a very low prevalence of H. pylori in the dyspeptic population, non-invasive testing for H. pylori loses its significance and empirical treatment with an antisecretory drug becomes a rational first step. CONCLUSIONS: The optimal approach to management of uncomplicated dyspepsia is dependent on the prevalence of H. pylori among the dyspeptic population. At the current prevalence rate, 'test and treat', followed by acid suppressive treatment in the case of persisting symptoms, is the most appropriate strategy.     

Review article: nitroimidazole resistance in Helicobacter pylori

The efficacy of a nitroimidazole-containing regimen for the treatment of Helicobacter pylori infection is decreased by nitroimidazole resistance. Nitroimidazoles are meta- bolized by H. pylori by several nitro-reductases of which an oxygen-insensitive NADPH nitroreductase encoded by the rdxA gene is the most important. Null mutations in this gene are associated with resistance.
Susceptibility testing to nitroimidazoles may give variable results. This is not only related to the slow growth under specific conditions, but also to variability in the activity of the other nitroreductases and the ability to deactivate toxic metabolites of an NI and to repair DNA damage. Moreover, co-infections with resistant and susceptible bacteria are frequently found. The presence of nitroimidazole resistance is related to the previous use of this drug. The prevalence of resistance is rising and nowadays 10–50% of the isolates are resistant.
Resistance reduces the efficacy of a treatment regimen to a variable degree. This is related to efficacy of the other components of the regimen and the treatment duration. Whether a nitroimidazole is still effective in resistant strains remains unresolved.
When nitroimidazole resistance is present, a nitro-imidazole-containing regimen should be avoided or a regimen with other highly effective components should be used.     

Cytochemical, functional, and proliferative characteristics of promonocytes and monocytes from patients with monocytic leukemia

This article deals with a prospective study on the cytochemical, functional, and proliferative characteristics of promonocytes and bone marrow and peripheral blood monocytes of 20 patients with acute monocytic leukemia and 7 patients with chronic monocytic leukemia. The results show a wide variation in the peroxidase and esterase activities in these cells, whereas the percentages of mononuclear phagocytes with Fc gamma and C3b receptors did not differ appreciably from those in normal individuals. A discriminant analysis of these data and corresponding data from normal individuals showed that a below-normal peroxidase activity of circulating monocytes has predictive value for the presence of monocytic leukemia; a below-normal esterase activity has less, but nevertheless some, predictive value in this respect. An increase in the percentage of circulating monocytes, a decrease in the percentage of Fc gamma or C3b receptors, and a decline in the ability to phagocytose bacteria has no predictive value for the presence of monocytic leukemia. The mean percentage of patients' promonocytes that incorporated 3H-thymidine amounted to 80.9%, which is close to the control value in normal individuals. The mean values for the labeling indices of cultured bone marrow and peripheral blood monocytes are 1.0% and 0.74%, respectively; when 3H-thymidine was added to whole blood, the labeling index of the monocytes amounted to 3.6%. These percentages are only a little higher than those found for monocytes of normal individuals. These results indicate that the majority of the circulating monocytes in acute and chronic monocytic leukemia are not actively dividing or blast cells.