Quantitative analysis of transforming growth factor beta isoforms mRNA in the human corneal epithelium

TGF-beta is an important mediator of cell growth, differentiation, and proliferation and plays a significant role in both normal and pathological corneal tissue. However, the quantitative relations between TGF-beta1, -beta2 and -beta3 isoforms in human cornea still remain unclear. Therefore, the aim of this study was to determine the gene expression profile of TGF-betas in order to evaluate quantitative relations between the examined transcripts in human corneal epithelium. Transcriptional activity of TGF-beta1, 2, 3, GAPDH and beta-actin genes was estimated on the basis of mRNA copy number per 1 microg of total RNA using the real-time QRT-PCR technique with the SYBR Green I chemistry. Specificity of RT-PCR reaction was confirmed by determination of the characteristic melting temperature for each amplimer. Additionally, the RT-PCR products were separated on 6% polyacrylamide gels and visualized with silver salts. Expression of all TGF-beta genes for the corneal epithelium was determined. Comparable analysis of mRNA copies/1 mug of total RNA for each TGF-beta isoform showed that: TGF-beta1 > TGF-beta2; TGF-beta3 > TGF-beta2; TGF-beta1 = TGF-beta3 (ANOVA test P < 0.0001; post-hoc Tukey's test: TGF-beta1 and TGF-beta2, P = 0.0306; TGF-beta3 and TGF-beta2, P = 0.0045; TGF-beta1 and TGF-beta3 NS). We found different expression of the TGF-beta1, -2 and -3 isoforms in the human corneal epithelium. Such differential expression of TGF-betas suggests that each of them may play a specific role in corneal tissue.

Human cytomegalovirus DNA level in patients with idiopathic pulmonary fibrosis

The objectives of the study were to estimate human cytomegalovirus (HCMV) DNA copy number in broncho-alveolar lavage cells, blood leukocytes, and serum of patients with idiopathic pulmonary fibrosis (IPF). The study groups consisted of 16 patients, newly diagnosed with IPF and never treated, (mean age 40.9 +/-11.0 yr; F/M-7/9) and in 16 adult healthy volunteers (mean age 36.8 +/-6.4 yr; F/M-4/12) used as controls. The HCMV DNA copy number was calculated by a Q-PCR method using TaqMan ABI PRISM 7700. We found that the prevalence of the HCMV DNA positive subjects in the patient group (75%) did not differ significantly from that in the control group (69%). We also found that in both patient and control groups the mean HCMV DNA copy number in BAL cells was significantly higher than that in blood leukocytes (log10=2.7 vs. 1.2 for patients and 2.8 vs. 0.9 for controls, respectively). However, a higher HCMV DNA copy number in blood serum was observed in IPF patients than in controls (log10=3.2 vs. 2.0, respectively). We conclude that the lungs play an important role in the human pathobiology of cytomegalovirus sustenance.

Use of ambulatory electrocardiography for the detection of paroxysmal atrial fibrillation in patients with stroke. Canadian Task Force on Preventive Health Care

BACKGROUND

Patients with stroke commonly undergo investigations to determine the underlying cause of stroke. These investigations often include ambulatory electrocardiography to detect paroxysmal atrial fibrillation. There is conflicting evidence in the literature regarding whether routine ambulatory electrocardiography should be performed in all or selected stroke patients. This paper reviews the available evidence on (1) the yield of ambulatory electrocardiography in detecting paroxysmal atrial fibrillation in patients with stroke or transient ischemic attack and (2) the effectiveness of anticoagulation in preventing recurrent stroke in patients with paroxysmal atrial fibrillation.

METHODS

A MEDLINE search for primary articles was performed, and the references were reviewed manually. In addition, citations were obtained from experts. The evidence was systematically reviewed using the evidence-based methodology of the Canadian Task Force on Preventive Health Care.

RESULTS

Ambulatory electrocardiography can detect atrial fibrillation not found on initial electrocardiogram in between 1% and 5% of people with stroke. Ambulatory electrocardiography is generally safe. The risk of recurrent stroke in the setting of paroxysmal atrial fibrillation is uncertain, but appears to be similar to that seen with chronic atrial fibrillation (about 12% per year). Therapy with warfarin may reduce this risk by about two-thirds as compared to placebo. The annual risk of major bleeding with warfarin therapy is between 1% and 3% but rates for individual patients depend on various specific risk factors.

INTERPRETATION

There is insufficient evidence to recommend for or against the use of ambulatory electrocardiography for the detection of paroxysmal atrial fibrillation in either selected or unselected patients with stroke (C Recommendation). There is fair evidence to recommend therapy with warfarin for patients with stroke and paroxysmal atrial fibrillation (B Recommendation).

Appropriateness of primary total hip and knee replacements in regions of Ontario with high and low utilization rates

OBJECTIVE

To compare the appropriateness of case selection for primary hip and knee replacements between two regions in Ontario: one with a high population-based utilization rate and one with a low rate.

DESIGN

Random audit of medical records sampled from hospital discharge abstracts, with subsequent implicit and explicit criteria-based assessments of the appropriateness of surgery.

STUDY POPULATION

People aged 60 years or over who underwent elective, single-joint, non-fracture-related, primary hip or knee replacement between Apr. 1, 1992, and Mar. 31, 1993, at one of seven hospitals in a high-rate region (comprising Brant, Huron and Oxford countries) or one of eight hospitals in a low-rate region (comprising the cities of Scarborough and Toronto).

INTERVENTIONS

Structured review of hospital medical records, with additional review of information from surgeons and family physicians' office charts if necessary. Three physicians reviewed patient data and rated the preoperative pain level and functional status of patients, with agreement among at least two reviewers. The proportion of inappropriate cases was then assessed according to explicit criteria defined by a multidisciplinary panel using the delphi process. Profiles of each case were also subjected to independent implicit review by two rheumatologists and two orthopedic surgeons.

OUTCOME MEASURES

Proportion of joint replacements deemed inappropriate in the high- and low-rate regions according to either the explicit criteria or the implicit review, as well as preoperative pain levels and functional status of patients in the high- and low-rate regions.

RESULTS

Hip replacements were more common among patients sampled in the low-rate region than among those in the high-rate region (57.3% v. 39.3%; p < 0.002), although the patients' baseline characteristics, including severity of preoperative pain and dysfunction, were otherwise similar between the regions. Inappropriate surgery, determined by explicit criteria, was equally uncommon in the two regions (6.4% and 6.1%). On implicit review, the two rheumatologists rated fewer cases as appropriate than did the two orthopedic surgeons (63.0% v. 80.0%; p < 0.001); however, the proportion of cases rated as inappropriate by the subspecialists was similar in the high- and low-rate regions (11.4% and 11.0%, respectively, by the rheumatologists, and 6.3% and 10.4%, respectively, by the orthopedic surgeons).

CONCLUSIONS

Patients selected for primary hip or knee replacement are similar in the high- and low-rate regions of Ontario. Inappropriate use of this procedure does not account for the high rate of surgery in some areas. Further studies will be required to determine which other factors account for the regional variations in the utilization rates and whether there is underservicing in low-rate areas.