Characteristics of peer reviewed clinical medicine journals

Many variations exist in editorial peer review practices in clinical medicine journals. These practices will become more crucial as medical journals make more of their contents available via the World Wide Web. This paper explores five fundamental dimensions of editorial peer review variations: (1) the extent to which manuscripts are subjected to peer review; (2) the sequence of decision points in the peer review process; (3) blinding practices; (4) acceptance rates for submitted manuscripts; and (5) guidelines stating editors' expectations of reviewers. Variations in editorial peer review practices make it difficult to define a "peer reviewed journal" in clinical medicine. Research in this relatively new area of inquiry has not established the relative strengths of each variation in relation to a journal's quality.

The small aortic root and the Medtronic Hall valve: ultrafast computed tomography assessment of left ventricular mass following aortic valve replacement

BACKGROUND AND AIMS OF THE STUDY

The selection of an appropriate size aortic valve substitute with respect to patient size and life-style, in the presence of a small aortic root, is problematic, and a decision to enlarge the aortic annulus is often arbitrary. An aortic valve substitute-patient mismatch may place an excessive load on the left ventricle resulting in residual left ventricular mass with attendant patient morbidity and mortality. The aim of this study was to assess the adequacy of the Medtronic Hall valve in the small aortic root using ultrafast computed tomography analysis of left ventricular mass.

MATERIALS AND METHODS

In 13 patients the smallest Medtronic Hall valves (size 20 and 21; measured internal orifice area of 2.01 cm2 for both) were used to replace the native aortic valve. All patients had aortic stenosis, and left ventricular hypertrophy was established by echocardiography. The mean body surface area was 1.8 +/- 0.2 m2 (range 1.50-2.06 m2) and the mean weight was 75 +/- 15 Kg (range 50-97 Kg). The mean preoperative New York Heart Association functional class was 3.54 +/- 0.5.

RESULTS

There was no operative or late mortality. At a mean follow up of 22 months after aortic valve replacement, the mean left ventricular mass index was 89 +/- 11.4 g/m2 (normal left ventricular mass index by ultrafast computed tomography = 97 +/- 14 g/m2) and mean New York Heart Association functional class was 1.6 +/- 0.8 (p (Binomial) = 0.0001 compared to preoperative). Doppler echocardiogram demonstrated a mean gradient across the prosthetic valve of 17 +/- 7 mmHg. There was no trend towards greater left ventricular mass index in patients with greater body surface area or weight. In no patient was the aortic annulus enlarged.

CONCLUSIONS

Trends from this preliminary data suggest that implanting the smallest Medtronic-Hall aortic valves (sizes 20 and 21) results in normal left ventricular mass following aortic valve replacement in patients up to a body surface area of 2.06 m2 and provides support for the notion that an aortic annulus enlarging procedure was not necessary in this group of patients.

Right to left interatrial shunting following balloon mitral valvuloplasty

A complication of balloon mitral valvuloplasty is development of left-to-right interatrial shunt. This report describes right-to-left interatrial shunting following balloon mitral valvuloplasty in a patient with mitral stenosis, tricuspid regurgitation and pulmonary hypertension.

Immunological capture of nucleic acid hybrids and application to nonradioactive DNA probe assay

Antibodies specific for DNA:RNA hybrids were coated onto polystyrene test tubes and applied to hybridization assays involving DNA and RNA. Synthetic DNA probes complementary to 16S rRNA of Campylobacter were labeled with biotin and hybridized to ribosomal RNA directly in lysates of bacterial cells. After hybridization, DNA:RNA hybrids were captured with immobilized anti-DNA:RNA antibody, and the biotinylated probe was detected with streptavidin-horseradish peroxidase (EC 1.11.1.7) conjugate. The assay was optimized to detect as few as 70,000 Campylobacter cells in a sample. We compared the utility of this hybridization assay with that of conventional microbiology methods by examination of 1448 stool samples from hospital clinical laboratories. The DNA hybridization assay had a sensitivity of 98.7% (75/76) and a specificity of 98.2% (1347/1372) and overall agreed with 98.2% of the conventional results for a test population that had a 5.2% incidence (76/1448) of Campylobacter infection. The assay is simple to perform and yields results within 2.5 h.

Immunological capture of nucleic acid hybrids and application to nonradioactive DNA probe assay

Antibodies specific for DNA:RNA hybrids were coated onto polystyrene test tubes and applied to hybridization assays involving DNA and RNA. Synthetic DNA probes complementary to 16S rRNA of Campylobacter were labeled with biotin and hybridized to ribosomal RNA directly in lysates of bacterial cells. After hybridization, DNA:RNA hybrids were captured with immobilized anti-DNA:RNA antibody, and the biotinylated probe was detected with streptavidin-horseradish peroxidase (EC 1.11.1.7) conjugate. The assay was optimized to detect as few as 70,000 Campylobacter cells in a sample. We compared the utility of this hybridization assay with that of conventional microbiology methods by examination of 1448 stool samples from hospital clinical laboratories. The DNA hybridization assay had a sensitivity of 98.7% (75/76) and a specificity of 98.2% (1347/1372) and overall agreed with 98.2% of the conventional results for a test population that had a 5.2% incidence (76/1448) of Campylobacter infection. The assay is simple to perform and yields results within 2.5 h.