The relative importance of thrombin inhibition and factor Xa inhibition to the antithrombotic effects of heparin

The relative importance of antithrombin and anti-factor Xa activities of heparin fractions required to achieve optimal antithrombotic effects is unknown. To study this, we measured the effects of standard heparin, an octasaccharide heparin fraction (anti-factor Xa activity only), and dermatan sulfate (antithrombin activity only) on the prevention of thrombosis and related this to their anticoagulant effects in vivo in rabbits. Thrombosis was measured as the incorporation of 125I- fibrinogen into tissue thromboplastin-induced thrombi using a Wessler- type model. Ex vivo changes in thrombin clotting time (TCT) were used as an index of antithrombin activity, and a chromogenic anti-factor Xa assay was used to measure anti-factor Xa activity. In addition, the ability of the three sulfated polysaccharides to simultaneously inhibit the generation of thrombin activity and to enhance the inactivation of the factor Xa added to initiate thrombin generation in plasma was determined. Standard heparin, in a dose of 10 anti-factor Xa U/kg, inhibited thrombus formation by 90%, prolonged the TCT by two seconds, and resulted in an anti-factor Xa level of 0.32 U/mL. The octasaccharide heparin fraction, in a dose of 10 anti-factor Xa U/kg, inhibited thrombus formation by 41%, had no effect on the TCT, and resulted in an anti-factor Xa level of 0.28 U/mL. Higher doses of the octasaccharide resulted in a further increase in the anti-factor Xa levels but had no further effect on thrombus formation. Dermatan sulfate, in a dose of 500 micrograms/kg, inhibited thrombus formation by 95%, but had no affect on the TCT. These results indicate that the antithrombotic effect achieved by inhibiting factor Xa is limited and that better antithrombotic effects are achieved by heparin or heparin- like substances capable of influencing the inactivation and/or the generation of thrombin.     

Invading of intrauterine contraceptive device into the sigmoid colon through uterine perforation caused by a blunt trauma

Intrauterine contraceptive device (IUCD) is relatively safe but still with some serious risks. Uterus perforation is rare and would be fatal. A case of Cu-7 IUCD invading into the sigmoid colon through uterine perforation caused by a pelvic blunt trauma was presented. Our case showed that uterus perforation by an IUCD could induce utero-sigmoid fistula which is likely to be missed. Imaging is required when the patients with IUCD present abdominal pain, particularly with a history of trauma.     

Measuring resistant-genotype transmission of malaria parasites: challenges and prospects

Increased gametocytemia in infections with resistant strains of Plasmodium species and their enhanced transmissibility are a matter of concern in planning and evaluating the impact of malaria control strategies. Various studies have determined weekly gametocyte carriage in response to antimalarial drugs in clinical trials. The advent of molecular biology techniques makes it easy to detect and quantify gametocytes, the stages responsible for transmission, and to detect resistant genotypes of the parasite. With the validation of molecular markers of resistance to certain antimalarial drugs, there is a need to devise a simpler formula that could be used with these epidemiological antimalarial resistance tools. Theoretical models for transmission of resistant malaria parasites are difficult to deploy in epidemiological studies. Therefore, devising a simple formula that determines the potential resistant-genotype transmission of malaria parasites should provide further insights into understanding the spread of drug resistance. The present perspective discusses gametocytogenesis in the context of antimalarial treatment and drug resistance. It also highlights the difficulties in applying the available theoretical models of drug resistance transmission and suggests Rashad’s devised formula that could perhaps be used in determining potentially transmissible resistant genotypes as well as in mapping areas with high potential risk for the transmission of drug-resistant malaria. The suggested formula makes use of the data on gametocytes and resistant genotypes of malaria parasites, detected by molecular techniques in a certain geographical area within a particular point in time, to calculate the potential risk of resistant genotype transmission.     

There is Limited Evidence to Support the Association between Severe Mental Illness and Poor Oral Health

ARTICLE TITLE AND BIBLIOGRAPHIC INFORMATION: Advanced dental disease in people with severe mental illness: systematic review and meta-analysis. Kisely S, Quek L-H, Pais J, Lalloo R, Johnson NW, Lawrence D. Br J Psychiatry 2011;199:187-93. REVIEWER: Hoda M. Abdellatif, BDS, MPH, Dr PH PURPOSE/QUESTION: How does the oral health status of individuals with severe mental illness compare with that of the general population? SOURCE OF FUNDING: Information not available TYPE OF STUDY/DESIGN: Systematic review with a meta-analysis LEVEL OF EVIDENCE: Level 2: Limited-quality, patient-oriented evidence STRENGTH OF RECOMMENDATION GRADE: Grade B: Inconsistent or limited-quality patient-oriented evidence.     

Prolapse surgery in octogenarians: are we pushing the limits too far?

Purpose

To report our experience with pelvic reconstructive surgery with transobturator mesh implants in elderly women.

Materials and methods

A total of 32 women aged >75 years with pelvic organ prolapse receiving anterior and/or posterior repair using transobturator mesh implants were included. Concomitant mid-urethral sling procedure was performed in 78 % women. Postoperative outcome data and quality-of-life measurements were recorded prospectively. Patients were followed for up to 24 months.

Results

Mean age at surgery was 82.8 ± 3.1 years. A total of 15 anterior repairs, 8 posterior repairs, and 9 posterior and anterior repairs were performed using transobturator mesh implants. Concomitant synthetic mid-urethral transobturator sling procedure was performed in 25 women (78 %). Mean operating time was 47.2 ± 22.3 min, and the mean hospitalization period was 5.9 ± 1.6 days. There were no systemic complications related to anesthesia or surgery. Two patients required intraoperative bladder suturing due to iatrogenic bladder lesion. There were no rectal injuries, no bleeding necessitating transfusion, voiding dysfunction, or erosions of synthetic implants. Pelvic floor testing at 24 months postoperatively showed 15 % of the patients presenting with stage II vaginal wall prolapse. Further, quality-of-life parameters, as measured by SF-36 questionnaire, were improved compared to baseline values.

Conclusions

Pelvic reconstructive surgery in elderly women is safe and enhances the quality of life. However, special caution should be paid to risks and benefits of such surgery in this patient population.