Cardiovascular autonomic dysfunction in normotensive awake subjects with obstructive sleep apnoea syndrome

Cardiovascular autonomic function in normotensive awake patients with obstructive sleep apnoea syndrome was studied in 21 normotensive (mean age 48 ± 14 years), drug-free men with obstructive sleep apnoea syndrome. Cardiovascular reflex tests with continuous blood pressure monitoring and biochemical indices were performed the morning after a standard polygraphic sleep recording. A group of 20 agematched (mean age 49 ± 19 years) normal subjects was used as controls. The obstructive sleep apnoea syndrome patients showed higher heart rate and noradrenaline plasma levels (p < 0.05) at rest and a higher blood pressure response to head-up tilt (p < 0.01), suggesting sympathetic overactivity. Respiratory arrhythmia, baroreflex sensitivity index and Valsalva ratio were significantly lower in the obstructive sleep apnoea syndrome group (p < 0.01) whereas the decrease in heart rate induced by the cold face test was significantly higher (p < 0.05) showing a blunting of reflexes dependent on baroreceptor or pulmonary afferents with normal or increased cardiac vagal efferent activity. These abnormalities in autonomic regulation may predispose obstructive sleep apnoea syndrome patients to cardiovascular complications like hypertension and cardiac arrhythmias.     

A flow cytometric assay for the detection of antiphospholipid antibodies

The data and the results obtained at the above symposium show that the flow cytometric method closely correlates with the standardized aCL bench ELISA and with the APhL ELISA kit. The aCL/aPS FACS kit is comparable in sensitivity to the APhL ELISA kit and standard aCL bench ELISA, but the aCL/aPS FACS kit is more specific than the standard anticardiolipin assay (particularly for the determination of aPS). In summary, the aCL/aPS FACS kit enables rapid (total run time < or = 1 hr) and simultaneous determination of aCL (aCL) and anti-PS antibodies of the IgG and IgM classes and combines good sensitivity and specificity in a single assay. The method is reproducible (intraassay variations < 5%). Furthermore, it is easy to transform into a partially or fully mechanized process and is well suited for laboratories that test large numbers of samples daily. The assay promises to be useful not only for detecting positive APS sera, but also in evaluating the significance of phospholipid specificity and antibody isotypes in patients with APS.     

Endovascular treatment in diseases of the thoracic aorta

PURPOSE: To determine whether endovascular treatment of thoracic aorta conditions can be an effective alternative approach to surgical repair. MATERIAL AND METHODS: July 1997 to February 1999, eighteen patients (16 men and 2 women; 58.6 +/- 14.8 years) presenting with different kinds of descending aorta conditions were selected for the endovascular treatment. All patients exhibited severe comorbid pulmonary and/or cardiovascular medical conditions which increased surgical risk. All implants were performed in the operating room under fluoroscopic and TEE guidance. Clinical and imaging follow-up was performed 1, 3, 6 and 12 months later. RESULTS: The endovascular treatment was successful in 17 cases. No deaths or major complications occurred. No leakage was evident at post-procedure angiography. The patients were discharged after 6 +/- 4 days. MRI or CT study performed before hospital discharge showed aneurysms exclusion in 16 patients. In the four cases of dissection, thrombosis of the false lumen was evident since the first follow-up study. In the group of patients (11 cases) with 6 months follow-up, the diameters of stented aortic segments decreased. No late leakage was observed and thrombosis was complete in all cases. DISCUSSION: The natural history of aortic aneurysms and dissection is progressive toward dilation and aortic rupture. Surgery of descending thoracic aorta is burdened with a mortality of 8-12% in elective cases and over 50% in emergency cases or aortic dissection. The endovascular treatment of aortic conditions was introduced in clinical practice in 1991 and literature data show that it is effective, with lower mortality and morbidity rates than surgical treatment. CONCLUSION: Our results stress the feasibility and effectiveness of endovascular procedure in the treatment of complex thoracic aorta conditions even in high risk patients. Thus, endovascular treatment of thoracic aorta can be considered an effective alternative approach to conventional surgery.     

Continuous versus intermittent portal triad clamping for liver resection: a controlled study

OBJECTIVE: The authors compared the intra- and postoperative course of patients undergoing liver resections under continuous pedicular clamping (CPC) or intermittent pedicular clamping (IPC). SUMMARY BACKGROUND DATA: Reduced blood loss during liver resection is achieved by pedicular clamping. There is controversy about the benefits of IPC over CPC in humans in terms of hepatocellular injury and blood loss control in normal and abnormal liver parenchyma. METHODS: Eighty-six patients undergoing liver resections were included in a prospective randomized study comparing the intra- and postoperative course under CPC (n = 42) or IPC (n = 44) with periods of 15 minutes of clamping and 5 minutes of unclamping. The data were further analyzed according to the presence (steatosis >20% and chronic liver disease) or absence of abnormal liver parenchyma. RESULTS: The two groups of patients were similar in terms of age, sex, nature of the liver tumors, results of preoperative assessment, proportion of patients undergoing major or minor hepatectomy, and nature of nontumorous liver parenchyma. Intraoperative blood loss during liver transsection was significantly higher in the IPC group. In the CPC group, postoperative liver enzymes and serum bilirubin levels were significantly higher in the subgroup of patients with abnormal liver parenchyma. Major postoperative deterioration of liver function occurred in four patients with abnormal liver parenchyma, with two postoperative deaths. All of them were in the CPC group. CONCLUSIONS: This clinical controlled study clearly demonstrated the better parenchymal tolerance to IPC over CPC, especially in patients with abnormal liver parenchyma.     

Autonomic nervous system function in myotonic dystrophy

Symptoms suggestive of dysautonomia are often reported in Myotonic Dystrophy (MD) patients. 12 patients with MD underwent cardiovascular function testing with assay of plasma noradrenaline (NA) and adrenaline (A) in supine rest condition and after orthostatic and cold stimulus. Statistical analysis showed no differences between MD patients and an age and sex matched control group.

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Sommario Nei pazienti affetti da Distrofia Miotonica si riscontrano spesso sintomi che suggeriscono un'alterata funzione del Sistema Nervoso Vegetativo. Abbiamo sottoposto a valutazione dei riflessi cardiovascolari e dei livelli ematici di catecolamine (adrenalina e noradrenalina) in condizioni basali, in psizione supina e dopo lo stimolo ortostatico e cold-pressor 12 pazienti affetti da Distrofia Miotonica. L'analisi statistica dei dati non ha mostrato differenze fra i pazienti e un gruppo di controllo comparabile per sesso ed età.

     

Isolated resection of segment 8 for liver tumors: a new approach for anatomical segmentectomy

HYPOTHESIS: Isolated resection of segment 8 (the right anterosuperior liver segment) is one of the most difficult hepatectomies to perform because of the location of segment 8, the relation between section 8 and the main intrahepatic vessels, and the absence of any anatomical landmarks. The few reports that deal with isolated resection of section 8 generally describe the use of a deep wedge transparenchymal transection. DESIGN: Original surgical technique. PATIENTS AND METHODS: The proposed technique is based on the extraparenchymal isolation and temporary clamping of the right anterior artery and portal branches, causing ischemic demarcation on the liver surface, which corresponds to the anatomical borders of the right paramedian segments (5 and 8). The liver is widely transected along the main hepatic fissure; then the pedicles of segment 8 are selectively ligated inside the parenchyma, and the resection is accomplished. This technique was used in 10 patients: 5 with hepatocellular carcinoma on cirrhosis and 5 with liver metastases. RESULTS: The mean operation time was 253 minutes. Intraoperative blood loss was minimal in all cases, and 7 patients did not require blood transfusion. Slight complications developed in 3 patients, and there was no operative death. The mean hospital stay was 9.3 days. CONCLUSIONS: This operative procedure is safe and ensures a complete anatomical resection of segment 8. The wide opening of the liver parenchyma facilitates hemostasis and makes it possible to obtain a correct resection margin. This technique is recommended for limited metastatic lesions located in segment 8 or for hepatocellular carcinoma arising in a cirrhotic liver.     

Migraine and cardiovascular diseases

Migraine has complex relationships with cerebrovascular and cardiovascular disorders but also with cardiac anomalies. Patients affected by migraine with aura have an increased prevalence of right-to-left shunt due to patent foramen ovale or pulmonary arteriovenous malformations. The association between ischemic heart disease, cardiovascular mortality and migraine remains unsettled. The debate focuses on a physiopathological link between migraine and cardiovascular diseases or a higher prevalence of risk factors in migraineurs.     

Comparison between the standard anticardiolipin antibody test and a new phospholipid test in patients with connective tissue diseases

OBJECTIVE: Antiphospholipid (aPL) antibodies are present in patients with systemic lupus erythematosus (SLE) and/or antiphospholipid antibody syndrome (APS) and are associated with recurrent thromboses, thrombocytopenia, and pregnancy losses. The presence of aPL antibodies is routinely tested using a standardized ELISA that utilizes cardiolipin as antigen (aCL ELISA). This test, although sensitive, is frequently positive in patients with nonrelated autoimmune disorders and some infectious diseases, making the test less specific. Thus there is a need for more specific tests for aCL with equivalent sensitivity to the standard assay. We evaluated the diagnostic utility of a new aPL antibody test kit with a unique phospholipid mixture designed to be more specific than the standard anticardiolipin ELISA. METHODS: aPL antibodies (IgG, IgM) were measured by both a standard ELISA and a new ELISA kit (APhL ELISA Kit, Louisville APL Diagnostics, Inc., Louisville, KY, USA) in the baseline serum from patients enrolled in a 5 year inception cohort, prospective study of early rheumatoid diseases: rheumatoid arthritis (N = 70), SLE (70), scleroderma (45), inflammatory myositis (36), and early undifferentiated connective tissue disease (CTD) (165). Diagnosis was based on standardized criteria and determined at the last study visit. A nested group of patients with Sjogren's syndrome (44) was also defined. Serum from 200 blood donors (BD) served as controls. Patients with known APS (33) and antinuclear cytoplasmic antibody positive renal vasculitis (52) were also studied. Laboratory personnel were blinded to sample diagnostic group. RESULTS: The kit was 90.9% sensitive for detecting APS. Seven patients missed by the kit all had standard aCL values < 40 PL units. Assuming controls do not have APS, the kit was 99.5% specific vs 96.0% for the standard assay. For the patients with CTD, the kit never detected a patient that was not also detected by the standard aCL assay. CONCLUSION: The APhL ELISA Kit appears to be more specific than the standard aCL ELISA without adding potential false positive results. The new test may be useful for followup study for patients found to be aCL positive by standard assays to increase specificity for aCL screening.     

Cardiovascular variability as a function of sleep–wake behaviour in narcolepsy with cataplexy

Hypocretin/orexin signalling varies among sleep–wake behaviours, impacts upon cardiovascular autonomic control and is impaired in patients with narcolepsy with cataplexy (NC). However, evidence concerning disturbed cardiovascular autonomic control in NC patients is contrasting, and limited mainly to waking behaviour. We thus investigated whether control of cardiovascular variability is altered in NC patients during wakefulness preceding sleep, light (1–2) and deep (3–4) stages of non‐rapid eye movement (NREM) sleep and rapid eye movement (REM) sleep. Polysomnographic recordings and finger blood pressure measurements were performed on nine drug‐free male NC patients and nine matched healthy control subjects during spontaneous sleep–wake behaviour in a standardized laboratory environment. Indices of autonomic function were computed based on spontaneous fluctuations of systolic blood pressure (SBP) and heart period (HP). During wakefulness before sleep, NC patients showed significant decreases in indices of vagal HP modulation, cardiac baroreflex sensitivity and amplitude of central autonomic (feed‐forward) cardiac control compared with control subjects. During NREM sleep, the negative correlation between HP and subsequent SBP values was greater in NC patients than in control subjects, suggesting a greater contribution of central autonomic commands to cardiac control. Collectively, these results provide preliminary evidence that autonomic control of cardiac variability by baroreflex and central autonomic (feed‐forward) mechanisms is altered in NC patients during spontaneous sleep–wake behaviour, and particularly during wakefulness before sleep.     

Epidemiological studies on Echinococcus in Pampas fox (Lycalopex gymnocercus) and European hare (Lepus europaeus) in Buenos Aires province, Argentina

In Argentina, hydatid disease caused by Echinococcus granulosus is widespread. The south of Buenos Aires province, Argentina, is one of the three regions where hydatidosis is endemic. Although domestic dogs and sheep are considered to be the main hosts for E. granulosus, the potential role of wildlife in the local transmission of E. granulosus has not been investigated. The aim of this study was to estimate the hydatidosis/echinococcosis prevalence in European hare (Lepus europaeus) and Pampas fox (Lycalopex gymnocercus), two abundant species with a strong predator–prey relationship in rural areas of Buenos Aires province using different diagnostic tests. A total of 61 fox intestines were examined, finding that 52 (85.2 %) harbored at least one helminth species. However, no adult or immature form of Echinococcus sp. was found in the intestinal contents. Coproparasitological analysis and Copro–ELISA followed by Copro–PCR were used as supplementary diagnostic tests. Only one (1.7 %) of 59 fecal samples was positive to Taeniidae eggs by coproparasitological analysis, but this same sample was negative by the Copro–ELISA test. The analysis by Copro–ELISA showed 6 of 57 (10.6 %) positive samples, but the Copro–PCR tests carried out on these samples were negative to E. granulosus. A total of 6,808 lungs, 3,576 livers, and 3,542 hearts of hunted hares were examined and palpated, but no structure resembling hydatid cysts were detected. Our results suggest that hares and Pampas foxes are not currently important wild reservoirs of E. granulosus in the studied area.