Changes in snoring characteristics after 30 days of nasal continuous positive airway pressure in patients with non-apnoeic snoring: a controlled trial.

BACKGROUND--A study was performed to evaluate the effect of discontinuation of nasal continuous positive airway pressure (NCPAP) treatment on snoring characteristics. METHODS--Eighteen non-apnoeic snoring subjects were randomly allocated to either a no treatment control group or an NCPAP treatment group. The control group was studied twice (baseline and day 30 of follow up). In the NCPAP group the level of NCPAP that abolished snoring was determined and part abolished snoring was determined and patients were placed on NCPAP every night for one month. A sleep study was performed on the first night without NCPAP after completing 30 days of treatment (follow up 1). A fourth polysomnographic study was performed 8-10 days after NCPAP was stopped (follow up 2) in six subjects. RESULTS--In both groups total sleep time (TST) and sleep architecture remained unchanged at the different visits. Baseline snoring characteristics in the two groups were similar. In the control group the mean (SE) number of snoring episodes/hour of sleep (snoring index) and the percentage of TST > 60 decibels (dB) were 380 (36)/h and 11.1 (2.0)% TST respectively at baseline, and was unchanged at follow up. In the NCPAP group the snoring index decreased from 387 (50)/h to 320 (57)/h after NCPAP therapy, but the % TSTS > 60 dB decreased from 10.3 (1.8)% to 7.4 (1.5)%. The snoring index and intensity returned to baseline values at follow up 2 (374 (74)/h, 9.8 (2.1)% TST). Changes in snoring characteristics could not be explained by changes in body position between the different sleep studies. CONCLUSIONS--NCPAP improves snoring but this effect is lost soon after stopping treatment.     

Immunology

A selection of interesting papers that were published in the two months before our press date in major journals most likely to report significant results in immunology.     

Metabolic myocardial viability assessment with iodine 123-16-iodo-3-methylhexadecanoic acid in recent myocardial infarction: Comparison with thallium-201 and fluorine-18 fluorodeoxyglucose

The best test presently available to ascertain residual viability within an infarct-related area involves the use of fluorine-18 fluorodeoxyglucose (FDG) to detect the persistence of some cellular metabolism. Rest reinjection of thallium-201 is a less accurate alternative but is easy to perform. Iodinated fatty acids, which are used with standard gamma cameras, are proposed as markers of cellular metabolism. This study was performed to assess the value of 16-iodo-3-methyl-hexadecanoic acid (MIHA) as a marker of the residual cellular metabolism by comparison with FDG in patients with a recent myocardial infarction, and to evaluate its contribution compared with the²⁰¹Tl stress-redistribution-reinjection technique. Stress-redistribution-reinjection²⁰¹T1 imaging, rest MIHA imaging and glucoseloaded FDG imaging were performed in 22 patients with recent myocardial infarction. Out of the 628 myocardial segments obtained from the left ventricular analysis, 400 were hypoperfused (relative uptake <0.75 of maximum uptake on stress²⁰¹T1 imaging), 177 of which were severely hypoperfused (relative uptake <0.50). Receiver operating characteristic (ROC) curves for predicting metabolic myocardial viability with FDG were derived from the results in respect of (a)²⁰¹T1 activity during exercise, redistribution and reinjection and (b) MIHA up-take, using the two FDG thresholds most commonly considered to define metabolic viability (0.50 and 0.60). Analysis of the 400 hypoperfused segments demonstrated that²⁰¹T1 reinjection was the most accurate test in predicting the presence of myocardial viability (area under the ROI curves=0.85 and 0.86 at the 0.50 and 0.60 FDG thresholds, respectively;P<0.05 vs other tests). The global predictive values of MIHA and²⁰¹T1 reinjection were, respectively, 0.87 and 0.89 at the 0.50 FDG threshold (NS), and 0.82 and 0.87 at the 0.60 FDG threshold (NS). When only the 177 severely hypoperfused segments were considered,²⁰¹T1 reinjection remained the most accurate test (accuracy 0.84 at the 0.50 FDG threshold and 0.82 at the 0.60 FDG threshold), while the accuracy of MIHA decreased significantly (0.78 at the 0.50 FDG threshold and 0.73 at the 0.60 FDG threshold,P<0.05 vs²⁰¹T1 reinjection). In all circumstances, MIHA was less specific than²⁰¹T1 reinjection for the detection of metabolic viability. In conclusion, in patients with recent myocardial infarction, MIHA accurately detects the persistence of metabolic viability, but is not superior to²⁰¹T1.     

Coronary atherosclerosis in cardiac transplant patients treated with total lymphoid irradiation.

BACKGROUND: Multiple episodes of rejection following cardiac transplantation have been associated with an increased incidence of coronary atherosclerosis. Total lymphoid irradiation (TLI) has been shown to be a successful treatment for persistent allograft rejection, but its effect on coronary arterial disease has yet to be evaluated. METHODS: From 1987 to 1999, 40 patients required TLI for persistent or recurrent allograft rejection following heart transplantation. Each patient's (Group 1, n = 31) post-transplant coronary angiograms were examined and compared with those of a control group (Group 2, (n = 32) matched for time of transplantation. Degree of coronary stenosis was assessed on a 6-point scale. All patients received induction therapy (rabbit anti-thymocyte globulin or OKT3) and standard triple immunosuppressive therapy. TLI (80 cGy x 10 fractions) was used for the treatment of recurrent or persistent rejection on the basis of clinical indications. Actuarial survival, number and treatment of rejection episodes, and severity of coronary artery disease were compared in each group. RESULTS: Recipient gender, age, race and cytomegalovirus (CMV) status at time of transplant, along with donor gender, CMV status and graft ischemia time, were similar in both groups. Group 1 donor age was younger than that of Group 2 (22.2 +/- 11.2 vs 31.5 +/- 13.6 years, p = 0.004), and the indication for surgery in Group 1 patients was more likely to be ischemic heart disease (15 of 31 vs 6 of 32, p = 0.02). Mean follow-up was 5.7 +/- 3.5 years in Group 1 vs 6.9 +/- 3.8 in Group 2 (p = NS). Group 1 had more rejection episodes (4.4 +/- 2.2 vs 2.3 +/- 2.0, p = 0.0002) and more steroid treatments (9.78 +/- 4.0 g vs 5.14 +/- 4.7 g, p < 0.0001), but less coronary artery disease compared with Group 2 (p = 0.035). CONCLUSIONS: Despite multiple episodes of rejection, patients treated with TLI after cardiac transplant appear to develop less coronary atherosclerosis than appropriately matched controls.     

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     

Comparison of the inflammatory response between miniaturized and standard CPB circuits in aortic valve surgery.

OBJECTIVE: One of the complications of CPB is the systemic inflammatory response syndrome (SIRS). Recent developments tend to minimize the biological impact of CPB in using miniaturized closed circuit with reduced priming volume and less blood-air interface. The benefit of these miniaturized closed circuits in terms of inflammatory response has been proved in coronary surgery. However, in open heart surgery, the CPB circuit is no more closed and the benefit of the miniaturized set-up could disappear. The aim of the study is to compare the SIRS between standard and miniaturized circuits in aortic surgery. METHODS: Forty patients who underwent singular aortic valve replacement were randomly assigned either to a standard CPB (group A, n=20) or to a miniaturized CPB (group B, n=20). Pertinent clinical and surgical data were collected. Hematological parameters (leukocyte and neutrophil counts) and biochemical parameters (C-reactive protein, cytokine tests) were determined pre-, on and post-CPB. RESULTS: There were an increase in leukocyte and neutrophil counts and a decline in hematocrit in both groups. In both groups, there was a raise after CPB, in C-reactive protein, IL-6, TNF-alpha, neutrophil elastase, and IL-10. However, the raises of elastase and TNF-alpha were significantly lower after the weaning of miniaturized CPB (116+/-46 ng/ml and 10+/-4 pg/ml, respectively) compared to standard CPB (265+/-120 ng/ml, P=0.01 and 18+/-7 pg/ml, P=0.03). The raise of IL-10 is also lower with miniaturized circuit (15+/-6 pg/ml) compared to standard circuit (51+/-26, P=0.004). CONCLUSIONS: This study demonstrates in aortic surgery, the lesser inflammatory response of a miniaturized CPB compared to a standard CPB. However, there is always some inflammation after CPB and a small bio-reactive free perfusion circuit is still to be found in open heart surgery.     

Physician knowledge of herbal toxicities and adverse herb-drug interactions.

OBJECTIVE: To determine how knowledgeable physicians are regarding the toxic effects and drug interactions of herbal remedies. METHODS: An anonymous voluntary demographic survey and 16-question, multiple-choice quiz was distributed at educational meetings of emergency medicine and internal medicine physicians. The primary outcome measures were to determine whether significant associations existed between quiz scores and the amount of clinical experience, or between quiz scores and self-assessed familiarity with the topic of herbal toxicities and adverse herb-drug interactions. RESULTS: A total of 142 surveys and quizzes were completed by 59 attending physicians, 57 resident physicians, and 26 medical students. The mean subject score on the quiz was only slightly higher than would have occurred from random guessing. Neither the amount of the subjects' clinical experience, nor their self-assessed familiarity with herbal toxicities and drug interactions correlated significantly with the score on the quiz. CONCLUSION: The physicians and medical students surveyed had little training in herbal toxicities and drug interactions. They generally rated their familiarity with these topics as 'poor', and their scores on the quiz bore out this assessment as correct. Educational efforts might improve physician knowledge of the adverse effects of herbal remedies.     

Ipsilateral cluster headache and chronic paroxysmal hemicrania: two case reports

We report two patients with ipsilateral attacks of cluster headache and chronic paroxysmal hemicrania. The first patient, a 33-year-old man, started having attacks of chronic cluster headache at the age of 27. At 33, they were replaced by typical attacks of ipsilateral chronic paroxysmal hemicrania which showed a dramatic improvement with indomethacin 150 mg daily. After two days of complete remission, cluster headache attacks reappeared and persisted until verapamil, 360 mg a day, was added to indomethacin. The second patient, a 45-year-old man, first developed attacks of episodic cluster headache at the age of 35. At 44, he experienced ipsilateral typical attacks of chronic paroxysmal hemicrania, and two months later attacks of cluster headache. Under verapamil 240 mg daily, attacks of cluster headache disappeared, but those of chronic paroxysmal hemicrania increased in frequency until indomethacin 150 mg daily was added. These observations suggest a close relationship but not a similarity between cluster headache and chronic paraoxysmal hemicrania, and show the practical therapeutic interest of maintaining this distinction.     

Hypointense transcerebral veins at T2*-weighted MRI: a marker of hemorrhagic transformation risk in patients treated with intravenous tissue plasminogen activator.

Prediction of hemorrhagic transformation (HT) in patients treated by intravenous recombinant tissue-type plasminogen activator (rt-PA) is a challenging issue in acute stroke management. HT may be correlated with severe hypoperfusion. Signal changes may be observed at susceptibility-weighted magnetic resonance imaging (MRI) within large perfusion defects. A signal drop within cerebral veins at T2*-weighted gradient-echo MRI may be expected in severe ischemia, and may indicate subsequent risk of HT. The authors prospectively searched for an abnormal visibility of transcerebral veins (AVV) within the ischemic area in patients with hemispheric ischemic stroke, before they were treated with intravenous rt-PA therapy. Any correlation between AVV and baseline clinical or MRI findings, or further HT, was noted. An AVV was present in 23 of 49 patients (obvious, n = 8; moderate, n = 15), and was supported by severe hemodynamic changes at baseline MRI. The AVV was correlated with the occurrence of parenchymal hematoma type 2 at computed tomography during the first week (r = 0.44, P = 0.002). Five of six type 2 parenchymal hematomas occurred in association with obvious AVV. At multiple regression analysis, two baseline MRI factors had an independent predictive value for HT risk during the first week: the AVV and the cerebral blood volume ratio (Nagelkerke R2 = 0.48).