Human erythrocyte volume is linearly related to cell concentration in blood

Summary In 253 normal male subjects mean corpuscular volume decreases as red cell count increases. The result is statistically significant (p<0.005).The work was supported by the Medical Research Council of Canada     

Barbed Sutures and Tendon Repair—a Review

Introduction

Traumatic tendon lacerations are a common problem encountered by hand surgeons worldwide. Although the use of barbed suture to repair tendon lacerations has gained theoretical popularity in recent years, there is little information available regarding the safety, efficacy, longevity, or complications encountered when used in tenorraphy. In this study, we review the available literature on the use of barbed suture in tendon repair.

Methods

Studies conducted between 1980 and 2014 were identified using several databases, including EMBASE, SCOPUS, MEDLINE, and Web of Science. Keywords used to search for appropriate studies included the following: barbed, v loc, quill, tendon, tendon injuries, suture, tenorraphy, injury, and laceration, in various combinations.

Results

Our initial literature search identified 47 articles, and 8 were deemed appropriate for review after applying our exclusion criteria. The data from each of the articles is reviewed for the following major categories:

1. Maximum load to failure
2. Mode of failure
3. Load to 2-mm gap
4. Change in cross-sectional area
5. Type of repair

Conclusions

Barbed suture tenorraphy has a myriad of theoretical advantages, supported by varying ex vivo studies, as compared to traditional techniques. However, due to the non-uniformity in current studies and the lack of available data in a live model, we are unable to argue for or against barbed suture tenorraphy. We believe our review provides the most in-depth analysis of barbed suture tenorraphy to date, illuminates the potential advantages of using barbed sutures, and highlights the need for further investigation into this technique.     

Inadvertent interchange of electrocardiogram limb lead connections: analysis of predicted consequences part II: double interconnection errors

Limb lead connection errors are known to be very common in clinical practice. The consequences of all possible single limb lead interconnection errors were analyzed in an earlier publication (J Electrocardiology 2008;41:84-90). With a single limb lead interconnection error, 6 combinations of limb lead connections are possible. Two of these combinations give rise to records in which the limb lead morphology is uninterpretable. Such records show a "flat line" in lead II or III. Three of the errors give rise to records that are fully interpretable once the specific interconnection error has been identified (although one of the errors cannot reliably be recognized in the absence of a previous record for comparison). One of the errors produces no change in the electrocardiogram recording. In all cases, the precordial leads are interpretable, although there are very minor changes in the voltages. This communication predicts the changes in limb lead appearances consequent upon all possible double limb lead interchanges and illustrates these with records electively taken with such double interconnection errors. There are only 3 possible double limb lead interconnection errors. In 2 of the possible combinations, interpretation of the limb leads is impossible, and each of these errors gives rise to a flat line in lead I. In the third combination, the record is fully interpretable once the abnormality has been identified. In all 3 types, the precordial leads are interpretable, although there are very minor changes in the voltages.     

The dependence of the modulation transfer function on the blocking layer thickness in amorphous selenium x-ray detectors

Blocking layers are used to reduce leakage current in amorphous selenium detectors. The effect of the thickness of the blocking layer on the presampling modulation transfer function (MTF) and on dark current was experimentally determined in prototype single-line CCD-based amorphous selenium (a-Se) x-ray detectors. The sampling pitch of the detectors evaluated was 25 microm and the blocking layer thicknesses varied from 1 to 51 microm. The blocking layers resided on the signal collection electrodes which, in this configuration, were used to collect electrons. The combined thickness of the blocking layer and a-Se bulk in each detector was approximately 200 microm. As expected, the dark current increased monotonically as the thickness of the blocking layer was decreased. It was found that if the blocking layer thickness was small compared to the sampling pitch, it caused a negligible reduction in MTF. However, the MTF was observed to decrease dramatically at spatial frequencies near the Nyquist frequency as the blocking layer thickness approached or exceeded the electrode sampling pitch. This observed reduction in MTF is shown to be consistent with predictions of an electrostatic model wherein the image charge from the a-Se is trapped at a characteristic depth within the blocking layer, generally near the interface between the blocking layer and the a-Se bulk.     

Association of Conventional and Exertional Coronary Heart Disease Risk Factors in 5,000 Apparently Healthy Men

Background and hypothesis: The aim of this study was to define the prevalence of previously undetected coronary heart disease among asmptomatic males, aged 30-65 years, by means of resting and exercise electrocardiography in conjunction with an analysis of conventional and exertional coronary risk factors. Methods: Between January 1985 and December 1989 we examined 5,000 clinically asymptomatic subjects. A detailed case history was obtained for each individual, followed by a complete physical examination, comprehensive blood (including lipid) profile, lung function tests, chest x-ray, a resting 12-lead electrocardiogram (ECG), and a maximal treadmill exercise ECG. Whenever possible, on-line computerized respiratory analysis (Beckman Metabolic Measurement Cart) was carried out during the exercise tests. Conventional and exertional coronary heart disease risk factors were also recorded. Results: A total of 162 persons (3.2%) showed abnormal S-T segment responses during the exercise or recovery period. Of these, 92 subjects underwent further investigations: coronary angiography (79), ²⁰¹thallium scanning (13), ²⁰¹thallium scanning followed by coronary angiography(7). Of the 86 patients who proceeded to cornoary angiography, 19 (22%) had either normal coronary artery anatomy or only insignificant disease. Among the 67 (78%) of patients with significant angiographically demonstrable disease, 26 received coronary artery bypass grafting, 7 underwent coronary angioplasty, and the remainder continued on medical management. Conclusions: These results are discussed in relation to a variety of conventional and exertional coronary risk factors.     

Increased risk of achilles tendon rupture with quinolone antibacterial use,especially in elderly patients taking oral corticosteroids

BACKGROUND: In several case reports, the occurrence of Achilles tendon rupture has been attributed to the use of quinolones, but the epidemiologic evidence for this association is scanty. METHODS: We conducted a population-based case-control study in the General Practice Research Database in the United Kingdom during the period 1988 through 1998. Cases were defined as all persons who had a first-time recording of an Achilles tendon rupture, and who had at least 18 months of valid history before the index date. As a control group, we randomly sampled 50 000 patients with at least 18 months of valid history who were assigned a random date as index date. RESULTS: We identified 1367 cases that met the inclusion criteria. The adjusted odds ratio (OR) for Achilles tendon rupture was 4.3 (95% confidence interval [CI], 2.4-7.8) for current exposure to quinolones, 2.4 (95% CI, 1.5-3.7) for recent exposure, and 1.4 (95% CI, 0.9-2.1) for past exposure. The OR of Achilles tendon rupture was 6.4 (95% CI, 3.0-13.7) in patients aged 60 to 79 years and 20.4 (95% CI, 4.6-90.1) in patients aged 80 years or older. In persons aged 60 years and older, the OR was 28.4 (95% CI, 7.0-115.3) for current exposure to ofloxacin, while the ORs were 3.6 (95% CI, 1.4-9.1) and 14.2 (95% CI, 1.6-128.6) for ciprofloxacin and norfloxacin, respectively. Approximately 2% to 6% of all Achilles tendon ruptures in people older than 60 years can be attributed to quinolones. CONCLUSIONS: Current exposure to quinolones increased the risk of Achilles tendon rupture. The risk is highest among elderly patients who were concomitantly treated with corticosteroids.