Cyclooxygenase-2 inhibitors enhance shear stress-induced platelet aggregation.

OBJECTIVES: We aimed to investigate the effect of parecoxib, a selective cyclooxygenase-2 (COX-2) inhibitor, on in vivo shear stress-induced platelet aggregation in a rat model of arterial bypass with focal narrowing. BACKGROUND: Long-term use of COX-2 inhibitors is associated with increased incidence of adverse cardiovascular events, especially in patients with a history of cardiovascular disease. These patients are at risk for thrombotic occlusion of arterial stenoses initiated by shear stress-induced platelet aggregation. METHODS: To mimic the combination of a tight arterial stenosis and high shear stress in rats, an extracorporeal shunt from carotid to femoral artery was compressed by the rollers of a pump. Platelet aggregation was continuously measured by a photometric detector in the shunt. RESULTS: Pretreatment with parecoxib (20 mg/kg) almost doubled shear stress-induced platelet aggregation (188% vs. 100% in control subjects, p = 0.0003). This was accompanied by a fall in plasma 6-keto-prostaglandin F(1alpha) from 100 +/- 25 pg/ml to 36 +/- 11 pg/ml (p < 0.0001). Enhanced platelet aggregation was also observed with high-dose aspirin (150 mg/kg) (146%; p = 0.02) but not with low-dose aspirin (25 mg/kg), which reduced aggregation (68%; p = 0.01). The effect of parecoxib was neutralized by low-dose (1 mg/kg) clopidogrel (from 188% to 92%; p = 0.0001), but not by low-dose aspirin (from 188% to 177%; p = NS). CONCLUSIONS: In the presence of an arterial stenosis, COX-2 inhibitors enhance shear stress-induced platelet aggregation. This enhancement was prevented by low-dose clopidogrel but not by low-dose aspirin. Clopidogrel might therefore allow COX-2 inhibitors to be used without raising risk of thrombotic occlusion.     

First evidence of fatal hantavirus nephropathy in India, mimicking leptospirosis.

Sir, In a recent Indian serosurvey [1], it was announced that ‘noreports of hantavirus infections in humans from India existed[before 2005]’. We wish to point out that serologicaland clinical evidence of hantavirus infection in India was alreadywell documented before 2005. From 1998 on, we screened leptospirosis-suspected cases in Indiafor the only known cosmopolitan hantavirus serotype, Seoul virus(SEOV). Wild rats are the reservoir     

Functional changes in the right and left ventricle during development of cardiac hypertrophy and after its regression.

OBJECTIVE: The aim was to determine left and right ventricular functional reserves and collagen concentration during the development of cardiac hypertrophy and after its regression. METHODS: Two experimental models of cardiac hypertrophy (chronic thyroxine or isoprenaline treatment of adult rats) were compared 24 h and five weeks after the agent was last given. Pressure changes in the left (right) ventricle before and after acute aortic (pulmonary artery) ligation were recorded in open chest anaesthetised animals. The difference in dP/dtmax after and before ligation was regarded as the functional reserve. The total collagen concentration was determined in both ventricles separately by means of hydroxyproline. RESULTS: Left and right ventricular weight increased by 20% and 30% respectively in the two models employed. In the thyroxine treated group, the functional reserve of the left ventricle rose very noticeably, whereas in the isoprenaline treated group it decreased. The right ventricular functional reserve did not differ from that in the controls in either of the two groups. The collagen concentration rose in the left ventricle in the isoprenaline group only. Five weeks after the last administration of the agent, cardiac mass and ventricular function did not differ from the control values in either of the models studied; the only exception was the incomplete regression of left ventricular hypertrophy and persistent structural and functional impairment of the left ventricle in the isoprenaline treated group. CONCLUSIONS: Our results indicate that hearts undergoing a comparable degree of experimental hypertrophy may have different functional and structural properties; significant differences were found between the right and left ventricular response. Regression of hypertrophy together with a reversal of ventricular function usually occurs unless the myocardium has received severe structural damage.     

The Sigma-trial protocol: a prospective double-blind multi-centre comparison of laparoscopic versus open elective sigmoid resection in patients with symptomatic diverticulitis

Backround  

Diverticulosis is a common disease in the western society with an incidence of 33–66%. 10–25% of these patients will develop diverticulitis. In order to prevent a high-risk acute operation it is advised to perform elective sigmoid resection after two episodes of diverticulitis in the elderly patient or after one episode in the younger (< 50 years) patient. Open sigmoid resection is still the gold standard, but laparoscopic colon resections seem to have certain advantages over open procedures. On the other hand, a double blind investigation has never been performed. The Sigma-trial is designed to evaluate the presumed advantages of laparoscopic over open sigmoid resections in patients with symptomatic diverticulitis.     

Early symptoms in the prodromal phase of delirium: a prospective cohort study in elderly patients undergoing hip surgery.

OBJECTIVES: The authors investigated prodromal delirium symptoms in elderly patients undergoing hip surgery. METHODS: This was a prospective cohort study in the setting of a large medical school-affiliated general hospital in Alkmaar, The Netherlands. Participants were patients undergoing hip surgery aged 70 and older at risk for delirium. Before surgery, patients were randomized to low-dose prophylactic haloperidol treatment or placebo. Daily assessments were based on patient interviews with the Mini-Mental State Examination and Digit Span test. The Delirium Rating Scale-Revised (DRS-R-98) was used to measure early symptoms during the prodromal phase before the onset of delirium. RESULTS: Data of 66 patients with delirium were compared with those of 35 at-risk patients who did not develop delirium: 14 of 66 patients (21%) had delirium on the day of surgery or early the day after, 32 of 66 (48%) on the second day, 14 of 66 on the third, and six of 66 (9%) on the fourth. The average DRS-R-98 total scores on day -4 to day -1 before delirium were 1.9 for the comparison group patients and 5.0, 4.3, 5.8, and 10.7 for patients with postoperative delirium. Multivariate analysis showed that the early symptoms memory impairments, incoherence, disorientation, and underlying somatic illness predict delirium. CONCLUSIONS: Most elderly patients undergoing hip surgery with postoperative delirium already have early symptoms in the prodromal phase of delirium. These findings are potentially useful for screening purposes and for optimizing prevention strategies targeted at reducing the incidence of postoperative delirium.     

T-cell vaccination in multiple sclerosis: update on clinical application and mode of action

Multiple sclerosis (MS) is a chronic inflammatory disease of the central nervous system (CNS). Autoreactive T cells specific for myelin antigens are considered to play a prominent role in the initiation of the local inflammatory response, ultimately leading to myelin damage. Several studies indicate that autoreactive T cells are not completely deleted in the thymus, but are part of the normal T cell repertoire. Accidentally activated autoreactive T cells, however, may not automatically lead to autoimmune disease. Several reports support the existence of peripheral regulatory networks that prevent the activation and expansion of pathogenic T cells. Anti-idiotypic and anti-ergotypic T cells are part of this regulatory network and are thought to control autoreactive T cells by recognition of certain clonotypic and ergotypic determinants. These clonotypic networks may not function properly in patients with MS. Immunization with attenuated autoreactive T cells, termed T cell vaccination (TCV), may enhance or restore the regulatory networks to specifically suppress the autoreactive T cells as shown in experimental autoimmune encephalomyelitis (EAE), a commonly used animal model for MS. In the past decade, TCV has been tested for MS in several clinical trails. This review summarizes these clinical trails and updates our current knowledge on the mode of action of T cell vaccination.     

Tunica media of aorta and pulmonary trunk in relation to internal calibres in transposition of great arteries,in aortic and pulmonary atresia and in normal hearts

Summary In a post mortem material of 17 cases of transposition of the great arteries (TGA) from patients with an age range from birth to two years and ten months after birth, the internal calibres of the great arteries and the ostia of the heart proved to be the same as in normal hearts. Furthermore, the media of the ascending aorta and pulmonary trunk showed no adaptation to the abnormal circulatory conditions in 15 cases of TGA with an age range from birth up to 51/2 months: in both great arteries the thickness of the tunica media and the packing density of its elastic fibres were the same as in normal hearts. However, adaptation of the tunica media of the pulmonary trunk to the abnormal circulatory conditions: increased media thickness, was found in the two remaining cases, older than 12 months.In 7 cases of pulmonary atresia (age from 1 day to 12 months) and in 9 cases of aortic atresia (age from 2 days to 37 days) the following observations were made. Vessels with reduced or absent function (ascending aorta in aortic atresia and pulmonary trunk in pulmonary atresia) showed a markedly different structure. In aortic atresia the internal calibre and thickness of the media of the ascending aorta were markedly reduced, whereas the packing density of the elastic fibres of the media remained the same as in normal hearts. In pulmonary atresia the pulmonary trunk showed large variations in internal calibre, whereas both media thickness and the packing density of its elastic fibres remained the same as in normal hearts. When the markedly enlarged single functional vessels (the pulmonary trunk in aortic atresia and the ascending aorta in pulmonary atresia) were compared no significant differences between their internal calibre, media thickness and the packing density of the elastic fibres were found indicating similar adaptation to the abnormal but comparable functional load of acting as sole arterial trunk.We are indebted to Prof. Dr. J. Moll for his help, to Dr. J.J. Willemse for statistical calculations, to Mr. P. Zondervan, M.D. (Dept. of Pathology I), for supply of material and to Mrs. L. Silvis for histo-technical assistance     

EXTEROCEPTIVE STIMULATION AS A CONTINGENT FACTOR IN THE INDUCTION AND ELICITATION OF DELAYED TYPE HYPERSENSITIVITY REACTIONS TO 1 CHLORO-, 2-4, DINITROBENZENE IN GUINEA PIGS

This study attempted to determine whether a prior period of “stress” would elicit the sensitization reaction of the skin to topically applied chemical agents. A subthreshold concentration of 1-chloro-, 2-4, dinitrobenzene (DNCB) was applied to the skin of 40 guinea-pigs, 20 of which had been subjected to repetitive electrical shocks throughout the previous 15 minutes. They were examined 24 hours later, and were retested with DNCB at another site after 9 days for signs of delayed sensitization. The stressed animals exhibited a more severe contact-reaction (p <. 01) after the induction test and also after the delayed test.     

Sutureless re-anastomosis by laparoscopy versus microsurgical re-anastomosis by laparotomy for sterilization reversal: a matched cohort study

BACKGROUND: Sutureless re-anastomosis per laparoscopy is an alternative for microsurgical re-anastomosis by laparotomy in the treatment of sterilized women with renewed child wish. Our aim was to compare pregnancy rates after both surgical techniques. METHODS: We performed a retrospective cohort study in which consecutive women who underwent sutureless re-anastomosis per laparoscopy were compared to women who underwent microsurgical re-anastomosis by laparotomy. Both procedures were performed in neighbouring hospitals in Northern-Brabant, The Netherlands, and women were matched for age. The primary outcome was time to ongoing pregnancy. RESULTS: Overall, we included 41 women who had sutureless re-anastomosis by laparoscopy, and 41 age-matched women who underwent microsurgical re-anastomosis by laparotomy. The number of women who conceived was 20 (15 ongoing pregnancies) in the sutureless laparoscopic group versus 26 (24 ongoing pregnancies) in the laparotomic group, a difference due to a longer follow-up period in the laparotomic group. Time to ongoing pregnancy was comparable in both groups (P=0.46), with 3 year cumulative ongoing pregnancy rates of 45 and 52% respectively. After adjustment for other prognostic factors, the fecundity rate ratio was 0.97 (95% CI 0.26-3.6), indicating a similar performance of the two techniques. CONCLUSION: The simplified stitchless laparoscopic procedure for reversal of tubal sterilization with the use of a tubal splint, clip fixation of the muscularis and fibrin glue resulted in a promising pregnancy rate, which was similar to the pregnancy rate obtained with the microsurgical re-anastomosis per laparotomy.