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PubMed1991

Implications of thrombosis and vasospasm in peripheral vascular disease.

Platelet activation releases not only thromboxane A2 but also serotonin, another vasoconstrictor agent that acts on blood vessels through a specific, 5-HT2 receptor. The development of ketanserin, the selective 5-HT2-receptor blocker, has made it possible to explore the role of serotonin in animal models and patients with endothelial injury and atherosclerotic disease. In animals models, growing collateral arterial vessels are exquisitely sensitive to the vasoconstrictor effects of serotonin, which are reversed by ketanserin. When endogenous platelet activation is induced by endothelial injury, a combination of ketanserin and a thromboxane synthesis inhibitor or antagonist is more effective at reversing collateral arterial vasoconstriction than either agent alone. More recently, studies at the time of angiography in humans with advanced atherosclerosis have shown that more than 50% display a dilator response to ketanserin in low doses: the response primarily involves dilatation of collateral arterial vessels, which is associated with a significant increase in calf blood flow. These findings support existing evidence that platelet products contribute to the ischemia syndromes due to atherosclerosis, and provide a promising approach to improved management.

Animals↗
PubMed1997

Color Doppler ultrasonography in the diagnosis of cavernous transformation of the portal vein.

OBJECTIVE: To improve diagnostic accuracy, we studied the use of color Doppler ultrasound (CDUS) in patients with cavernous transformation of the portal vein (CTPV). SUBJECTS AND METHODS: In 18 patients, the usefulness of CDUS was compared with that of B-mode US for visualizing and diagnosing CTPV. Sensitivity for detecting CTPV on B-mode US, CT, and CDUS was also compared in 14 patients who underwent angiography which showed typical findings of CTPV. In addition, we classified each patient based on the morphologic appearance in the ultrasound examination and correlated those findings with the etiology. RESULTS: CDUS proved to be superior to B-mode US in identifying collateral channels and was highly sensitive for detecting CTPV in 17 (94%) of the 18 patients. In comparison with angiography performed in 14 patients, B-mode US detected CTPV in 9 (64%) patients, contrast-enhanced CT in 7 (50%), and CDUS in 13 (93%), indicating that CDUS was the most reliable diagnostic tool. It was also possible to assess the etiology of CTPV using a combination of color Doppler findings. Detection of arterial flow patterns within the portal vein thrombus correlated with malignant findings on histologic examination, whereas benign thrombi showed no flow signals. CONCLUSION: CDUS proved to be a reliable and useful modality for diagnosing CTPV and evaluating the etiology of this entity.

Adult↗
PubMed1992

Membranous obstruction of the inferior vena cava: comparison of findings at sonography, CT, and venography.

OBJECTIVE: Membranous or segmental obstruction of the inferior vena cava is one of the common causes of chronic Budd-Chiari syndrome. In this study, the venographic findings are compared with the results of sonography and CT in order to ascertain their role in the management of these cases. MATERIALS AND METHODS: Fifteen patients with membranous (n = 8) or segmental (n = 7) obstruction of the inferior vena cava who had been examined with sonography and CT were studied retrospectively. Diagnosis was made at surgery (n = 3) or by venacavography (n = 12). Sonographic findings were analyzed on the basis of the initial report, and CT findings were reviewed retrospectively with knowledge of the sonographic findings. RESULTS: Sonography showed membranous obstruction (n = 5), segmental cordlike obstruction (n = 3), and unspecified obstruction (n = 5) of the inferior vena cava, while CT showed a flap of the membrane (n = 1) and segmental narrowing or obstruction of the inferior vena cava (n = 7). In the remaining cases, the inferior vena cava either appeared normal (n = 6) or was not visualized (n = 1) on CT or was not described in the sonographic report (n = 2). In nine cases, CT showed one or several tiny calcific foci in the inferior vena cava. Sonography showed obliteration of at least one hepatic vein (n = 8) and of intrahepatic collateral vessels (n = 12), whereas CT was less sensitive in evaluating obliteration of intrahepatic veins (n = 4) and collateral vessels (n = 7). Sonography and CT both showed hepatic masses (n = 6), evidence of liver cirrhosis and portal hypertension (n = 14), hepatomegaly (n = 14), enlargement of the caudate lobe (n = 9), and intraabdominal (n = 11) and abdominal wall (n = 15) collateral vessels. CONCLUSION: Sonography was superior to CT in delineating pathologic venous anatomy of the inferior vena cava and hepatic veins whereas CT was better in evaluating hepatic cirrhosis and tumor. We believe that these techniques are useful complements to venography in the diagnosis and management of these cases.

Adolescent↗
PubMed1993

CT diagnosis of superior vena cava syndrome: importance of collateral vessels.

OBJECTIVE: The purpose of this study was to evaluate the importance of collateral vessels in the CT diagnosis of superior vena cava syndrome. MATERIALS AND METHODS: Forty-seven patients with CT evidence of obstruction or compression of the superior vena cava or its major tributaries were included in this study. Contrast-enhanced CT scans had been obtained with a combined bolus and drip-infusion technique. We evaluated the CT scans, with particular attention to the presence of collateral vessels (and if present, their location), without knowing the patients' clinical histories. On reviewing the patients' charts, we found 23 patients with signs or symptoms of superior vena cava syndrome. We then correlated the presence of collateral vessels with the presence of signs and symptoms of superior vena cava syndrome. To verify the frequency of visible collateral vessels in healthy subjects, we also evaluated CT scans of 50 control subjects who did not have mediastinal disease or signs and symptoms of superior vena cava syndrome. RESULTS: Collateral vessels were seen on CT scans in 24 patients. Among the 23 patients who had signs and symptoms of superior vena cava syndrome, 22 patients had CT scans that showed collateral vessels. Two cases were false-positive and one was false-negative. The presence of collateral vessels, regardless of the number and location of the vessels shown on CT scans, was highly accurate as a predictor of superior vena cava syndrome, with a sensitivity of 96% and a specificity of 92%. Collateral vessels were seen in three (6%) of the 50 control subjects. CONCLUSION: We conclude that the presence of collateral vessels is a highly sensitive and specific CT sign of superior vena cava syndrome.

Adolescent↗
PubMed1996

Dose-dependent effect of endothelin-1 on blood flow to normal and collateral-dependent myocardium.

BACKGROUND: Plasma levels of endothelin-1 (ET-1) increase during ischemia and could potentially contribute to impairment of myocardial blood flow (MBF). Because collateral vessels demonstrate enhanced responsiveness to certain vasoconstrictors, blood flow to collateral-dependent myocardium could be particularly sensitive to increases in ET-1 levels. METHODS AND RESULTS: Studies were performed in 13 dogs in which collateral vessel development was produced by fluoroscopic embolization of the midleft anterior descending coronary artery with a hollow plug 4 to 6 weeks before the study. MBF was measured with radioactive microspheres at baseline and during 30-minute infusions of ET-1 (1, 10, and 100 ng/min) into the left main coronary artery. Because ET-1 stimulates endothelial prostacyclin release, aortic and coronary sinus levels of ET-1 and 6-keto-prostaglandin F1 alpha were measured at the end of each infusion. ET-1 increased MBF from 0.82 mL.min-1.g-1 at baseline to 0.92 mL.min-1.g-1 at 10 ng/min (P < .05), which corresponded to a coronary plasma concentration of 73 +/- 16 pg/mL. Blood flow in the collateral zone was less (0.74 mL.min-1.g-1) than in the normal zone (P < .05) and did not increase at an ET-1 dose of 10 ng/min. MBF in the normal and collateral zones significantly decreased when ET-1 was increased to 100 ng/min, corresponding to a coronary sinus concentration of 175 +/- 45 pg/mL (P < .05). ET-1 produced dose-related increases in aortic and coronary sinus 6-keto-prostaglandin F1 alpha and the transcoronary difference (P < .05). To assess the importance of prostacyclin in opposing the vasoconstriction produced by ET-1, additional studies were performed after cyclooxygenase blockade with indomethacin. After indomethacin administration, ET-1 (10 ng/min) caused a 120 +/- 23% increase in collateral vascular resistance (P < .05) and abolished the vasodilation that this dose produced in the normal zone. CONCLUSIONS: Blood flow to normal myocardium is increased at moderate plasma elevations of ET-1, whereas collateral blood flow is unchanged. Only at significantly elevated plasma concentrations of ET-1 is blood flow to normal and collateral-dependent myocardium impaired. Coronary endothelial production of prostacyclin in response to increasing concentrations of ET-1 represents an important means of blunting the vasoconstrictor properties of ET-1 in the canine coronary circulation. Coronary collateral vessels demonstrate a much greater dependence on prostacyclin production in blunting the vasoconstrictor properties of ET-1.

6-Ketoprostaglandin F1 alpha↗
PubMed1994

[Thallium-dipyridamole in acute myocardial infarction treated by thrombolysis: diagnostic and prognostic value].

BACKGROUND: The management of patients who received thrombolytic therapy for acute myocardial infarction is still controversial. It is not clear if the strategies usually followed after myocardial infarction for risk stratification have the same value when applied to patients treated with thrombolysis. METHODS: To assess the diagnostic and prognostic value of dipyridamole thallium-201 scintigraphy in the "thrombolytic era", we studied 110 consecutive patients younger than 75 recovering from first uncomplicated acute myocardial infarction treated with thrombolytic agents. Patients with early angina, recurrent acute myocardial infarction, heart failure, life-threatening arrhythmias, non Q wave myocardial infarction were excluded. Ninety patients were treated with streptokinase, 14 with rtPA, 6 with APSAC: All patients underwent dipyridamole thallium scintigraphy with standard dose and coronary angiography before discharge (10-20 days). Ninety-nine patients underwent exercise test. All patients were followed-up for 22 +/- 9 months (range 8-42). Perfusion abnormalities were classified as reversible (totally or partially) defects or persistent defects and within or outside the infarct zone. RESULTS: Fifty-eight patients developed anterior and 52 inferior acute myocardial infarction. Coronary angiography showed single vessel coronary artery disease in 66 patients, multivessel disease in 34, and normal coronary arteries or sub-critical stenosis in 10. No major complications (death, myocardial infarction, threatening arrhythmias, prolonged severe hypotension) occurred after dipyridamole infusion. Sixty-two patients had reversible perfusion defects at thallium scanning (34 within the infarct zone, 21 within and outside the infarct zone, 7 outside); 38 patients had persistent defects; 10 patients had a normal scintigraphic pattern. The diagnostic value of homozonal perfusion reversible defects for identifying a patent infarct-related vessel was poor (sensitivity 69.7%, specificity 64.7%). The diagnostic values of the same scintigraphic pattern improved in detecting patent infarct-related artery with residual critical stenosis (sensibility 75.4%, specificity 77.3%); in all the false positive cases (reversible defects within the infarct zone and occluded infarct-related artery) a good collateral flow was present. The sensitivity of reversible defects outside the infarct zone in detecting multivessel disease was 64.7% vs 56.3% of exercise test; the specificity was 92% vs 64%; the positive predictive value 78.6% vs 44%; the negative predictive value 85.3% vs 74.5%; the diagnostic accuracy 83.6% vs 61.4%. During the follow-up 2 deaths, 7 recurrent myocardial infarction, 1 sustained ventricular tachycardia, 1 heart failure, 13 recurrence of unstable angina and 9 revascularization procedures occurred among patients with reversible defects (either within or outside the infarct zone) at thallium scanning. One recurrent myocardial infarction, 4 recurrence of unstable angina and 2 revascularization procedures were the events among patients with persistent defects or normal scintigraphic pattern (p < 0.001). Ischemic events occurred with similar frequency in patients with reversible perfusion defects within the outside the infarct zone (55% vs 50%, NS). CONCLUSIONS: Dipyridamole thallium-201 scintigraphy performed after uncomplicated myocardial infarction treated with thrombolytic agents is a valuable diagnostic tool in identifying viable jeopardized myocardium within the infarct zone perfused by a patent but critically narrowed vessel; it shows better diagnostic accuracy in detecting multivessel disease than does the exercise test and is able to identify a subset of patients at risk for future ischemic events after thrombolytic therapy.

Adult↗
PubMed1996

[Detection of severity of coronary stenosis by quantitative myocardial tomography with Tc-99m-MIBI at rest].

To evaluate the role of myocardial tomography with Tc-99m-MIBI (MB) in detecting abnormal coronary arteries, 34 patients with myocardial infarction underwent resting quantitative SPEC with MB and coronary arteriography within one month. When segmental MB uptake was < 560% of the left ventricular peak activity, there was 88% probability that a totally occluded or severely stenosed coronary artery (stenosis > 90%) was involved. There was 82% probability of finding no significant stenosis of coronary arteries in the normal myocardial segments. In the myocardial segments supplied by occluded coronary arteries, there was significantly higher MB uptake in the segments with good collateral circulation as compared with those subtended by a vessel totally occluded with poor collateral circulation (P < 0.05). The sensitivity and specificity of detecting abnormal coronary artery by quantitative analysis of myocardial tomography was 87% and 90% respectively. It is suggested that quantitative analysis of myocardial tomography with MB can differentiate between myocardial segments supplied by severely stenosed and normal coronary artery and evaluate the existence of collateral circulation.

Aged↗
PubMed2001

Chloroaluminum phthalocyanine tetrasulfonate delivered via acid-labile diplasmenylcholine-folate liposomes: intracellular localization and synergistic phototoxicity.

Folate-diplasmenylcholine (1,2-di-O-(Z-1'-hexadecenyl)-sn-glycero-3-phosphocholine; DPPlsC) liposomes have been shown to greatly enhance the potency of water-soluble antitumor agents via a selective folate-mediated uptake and acid-catalyzed endosomal escape mechanism (Rui et al. J. Am. Chem. Soc., 1998; 120:11213--18). This study describes an adaptation of this strategy for the delivery of chloroaluminum phthalocyanine tetrasulfonate ([AlPcS(4)](4-)), a water-soluble sensitizer used in photodynamic therapy, in a binary targeting scheme designed to enhance both its tumor selectivity and phototoxicity. [AlPcS(4)](4-)/DPPlsC:folate liposomes (9.8 microM bulk concentration, 2.5 mM intraliposomal concentration) were substantially more phototoxic to folate-deficient KB cells than 12.5 microM free [AlPcS(4)](4-) after a 30 min irradiation (630-910 nm). Considerable differences in phototoxicity were observed, however, between the commercially-available AlPcS(4)(4-) and an HPLC purified sample of [AlPcS(4)](4-) due to an increased tendency for the latter to aggregate. Experiments with [AlPcS(4)](4-)/DPPC:folate and folate-free [AlPcS(4)](4-)/DPPlsC liposomes (acid-insensitive and non-targeted controls, respectively) showed significantly reduced phototoxicities under the same illumination conditions. Our results imply that higher concentrations of water-soluble sensitizers can be delivered to target cells using the folate receptor-mediated pathway, which can change both the biodistribution and intracellular localization of the sensitizer when acid-labile DPPlsC liposomes are used as the delivery vehicle. Potential advantages of this approach include the use of lower bulk [AlPcS(4)](4-) concentrations, rapid plasma clearance of free [AlPcS(4)](4-), and better phototoxic responses, due to higher intracellular [AlPcS(4)](4-) concentrations combined with reduced collateral photodamage arising from misguided sensitizer accumulation, thereby enhancing the selective phototoxicity of PDT treatments.

Aluminum↗
PubMed1999

Diagnosis of the nutcracker syndrome with color Doppler sonography: correlation with flow patterns on retrograde left renal venography.

OBJECTIVE: Our objective was to confirm flow patterns of the left renal vein and assess the usefulness of color Doppler sonography in the diagnosis of the renal vein entrapment, or nutcracker, syndrome. SUBJECTS AND METHODS: Forty-four patients with hematuria of unknown origin underwent color Doppler sonography, renal arteriography, retrograde left renal venography, and renocaval pressure measurement. The flow patterns were classified according to the presence or absence of distended left renal veins on sonograms and collateral veins on retrograde venograms. The sensitivity and specificity of color Doppler sonography for revealing the nutcracker syndrome were assessed by analyzing pressure gradients in combination with the venograms, which were used as the gold standard. RESULTS: Twenty-one nondistended left renal veins were seen, including 19 (43%) without collateral veins or hypertension and two (5%) with collateral veins but without hypertension (long-term nutcracker syndrome). The 23 distended left renal veins included seven without collateral veins or hypertension and one with hypertension but without collateral veins (early nutcracker syndrome). The remaining 15 distended left renal veins with collateral veins included 11 (25%) with borderline hypertension (partially compensatory status of the syndrome) and four (9%) with hypertension (noncompensatory status of the syndrome). The sensitivity and specificity of color Doppler sonography for revealing the nutcracker syndrome were 78% and 100%, respectively, when color flow in collateral veins was included in the diagnostic criteria. CONCLUSION: The nutcracker syndrome can exist in either nondistended or distended left renal veins. However, normal flow also can exist in distended left renal veins. The ability of color Doppler sonography to reveal color flow in collateral veins is useful for the noninvasive diagnosis of the nutcracker syndrome.

Adolescent↗
PubMed1987

Thromboxane contributes to the immediate antigenic response of canine peripheral airways.

The actions of specific humoral mediators in the immediate response of the canine peripheral airways to antigen challenge are not well understood. Using a method which allows localized exposure of the peripheral lung to antigen, we investigated the role of locally released thromboxane A2 (TxA2) in the immediate response of collateral airways to aerosolized antigen. In dogs with native sensitivity to Ascaris suum antigen, resistance to flow through the collateral system (Rcs) was measured using a wedged bronchoscope technique. Local administration of antigen aerosol (25 microliters, 1:10,000 dilution) produced a gradual increase in Rcs which reached a maximum of 365% of base line in 4-8 min. Analysis of bronchoalveolar lavage fluid obtained from the exposed segment at the peak of the response demonstrated significantly more TxB2 compared with control lavage samples (41.8 +/- 7.8 pg/ml vs. 27.9 +/- 8.3; P less than 0.025). After inhibition of thromboxane synthase with UK-37,248 (3 mg/kg iv) or OKY-046 (5 mg/kg iv), the increase in Rcs was significantly reduced at 40 s (P less than 0.001) and 2 min (P less than 0.01) after antigen delivery, and the maximal increase was attenuated by 41% (P less than 0.005). In contrast, the magnitude and time course of the airway response to aerosols of a stable thromboxane analog (U-46619) were not affected by blockade. Despite a similar attenuation (42%) of the maximal increase in Rcs by sodium meclofenamate (3 mg/kg iv), this cyclooxygenase inhibitor had no effect on the time course of the antigenic response.(ABSTRACT TRUNCATED AT 250 WORDS)

Airway Resistance↗
PubMed1999

Three-dimensional helical CT of pulmonary arteries in infants and children with congenital heart disease.

OBJECTIVE: The purpose of our study was to determine the value of three-dimensional reconstructed helical CT in the assessment of the pulmonary arteries in infants and children with complex congenital heart disease. MATERIALS AND METHODS: Twenty patients were examined with contrast-enhanced helical CT. Three-dimensional reconstructions were performed with multiplanar reformations, maximum intensity projection, and shaded-surface display. Correlation was made with 19 echocardiograms and 14 cineangiocardiograms. All imaging studies were reviewed independently for the following parameters: the caliber of the main and branch pulmonary arteries and their confluence, the presence of stenosis, the number and caliber of aortopulmonary collaterals, and the patency of vascular shunts and conduits. Surgical confirmation, which was used as the reference standard, was available in all patients. RESULTS: Helical CT was as accurate as angiocardiography in revealing stenotic and nonconfluent central pulmonary arteries and in revealing aortopulmonary collaterals (overall CT test parameters: sensitivity, 90%; specificity, 100%; accuracy, 93%).Three-dimensional rendition did not improve the accuracy of CT. The patency of shunts was shown equally well with CT as with angiography, but CT showed thrombosis more directly. Echocardiography was the least accurate technique in revealing pulmonary artery anatomy (accuracy, 65%), primarily because a relatively large number of studies were technically unsatisfactory to assess the study parameters. CONCLUSION: Helical CT angiocardiography with three-dimensional reconstruction is superior to echocardiography for the noninvasive assessment of pulmonary artery anatomy in patients with complex congenital heart disease. Helical CT may be used as a complementary technique and occasionally as a substitute for the diagnostic imaging portion of cardiac catheterization with cineangiocardiography.

Angiocardiography↗
PubMed1987

Collateral arterial tree and responses to serotonin.

Growing collateral arterial blood vessels are super-sensitive to serotonin. Advanced atherosclerosis causes platelet activation, and activated platelets release sufficient serotonin that collateral arterial spasm occurs as a response. The development of ketanserin, the 5-HT2-receptor blocker, has both identified the receptor responsible for the arterial spasm and provided new approaches to treatment.

Animals↗
PubMed1990

[Double-contrast arthrography of the knee in traumatic capsular-ligamentous lesions. A critical review].

The authors conducted a statistical study and a critical review on a series of 1,300 patients examined with double-contrast fluoroscopically guided knee arthrography using a simple examination technique. Arthrographic diagnoses were subsequently compared with arthrotomic (500 patients), arthroscopic (350 patients), and clinical (450 patients) diagnoses. The critical review pointed out the high diagnostic accuracy (90%) and the good sensitivity (87%) of arthrographic examination in patients affected with pathologic conditions of the cruciate ligaments. In collateral ligament diseases and in capsular ruptures arthrographic sensitivity was not as high but still acceptable (74%). Capsular tears and medial collateral ligament tears can be identified when contrast medium is seen leaking from the knee joint. Cruciate ligament tears may be partial or complete: if a tear is partial the synovial surface of the cruciate ligament cannot be identified the cruciate ligament is wavy, lumpy, or focally thin, while in complete tears the synovial surface of the cruciate ligament cannot be identified either entirely or partially.

Arthrography↗
PubMed1996

The diagnostic validity of magnetic resonance imaging in acute knee injuries with hemarthrosis. A single-blinded evaluation in 69 patients using high-field MRI before arthroscopy.

Sixty-nine patients with traumatic knee hemarthrosis were evaluated an average of 3 days after trauma by high field (1.5T) magnetic resonance imaging (MRI) using sagittal T1, T2-weighted and coronal 3D-gradient echo images. All knees were arthroscopically examined shortly afterwards. The diagnostic validity of MRI for intraarticular pathology was determined using arthroscopy as golden standard. All patients had pathological findings on arthroscopy. The injuries were sports-related in 77% of the cases. MRI was highly sensitive (86%) and specific (92%) for diagnosis of anterior cruciate ligament tears. Diagnosis of medial meniscal tears showed a 74% sensitivity and 66% specificity. MRI detected lateral meniscal tears in 50% with an 84% specificity. As such, MRI missed 10 significant meniscus ruptures requiring surgical treatment. The sensitivity for partial or total medial collateral ligament tears was 56%, the specificity 93%. Rupture of the medial retinaculum in cases with patellar dislocation or significant damage of articular cartilage were only detected by MRI in a few cases (27% and 20% sensitivity, respectively). MRIs low diagnostic validity for intraarticular pathology with hemarthrosis may be attributed to the shifting paramagnetic properties of the blood remains and catabolic processes in meniscal and chondral tissues during the hemoglobin degradation process. Accordingly, MRI, with the technique used, could neither replace arthroscopy in the diagnosis and screening of acute knee injuries, nor select patients with need for immediate arthroscopic meniscal surgery.

Acute Disease↗
PubMed2002

Dual action of olivocochlear collaterals in the guinea pig cochlear nucleus.

Axons of olivocochlear neurones in the superior olivary complex terminate on hair cells of the cochlea, reducing the sensitivity to sound. These axons also have collateral branches to neurones in the cochlear nucleus, the first processing centre in the brainstem. Anatomical data show that these collaterals terminate mainly in the granule cell area but their precise neuronal targets and the effects they might have are unknown. We have studied the effects of these collaterals in guinea pigs, by electrically stimulating the olivocochlear axons at the floor of the IVth ventricle while recording single neurone responses in the cochlear nucleus. We eliminated the peripheral effects of olivocochlear stimulation either by destruction of the target receptor cells using chronic administration of kanamycin, or by acute perfusion of the cochlea with strychnine, a specific blocker of the postsynaptic receptors. Electrical stimulation of the olivocochlear axons in normal animals caused a variety of effects on cochlear nucleus neurones. In some neurones, there was suppression of spontaneous firing and a reduction in sensitivity to sound, while in others there was an excitatory effect of olivocochlear axon stimulation. When the peripheral olivocochlear action was eliminated, we still found both inhibition and excitation in the cochlear nucleus. These results show that the effects of olivocochlear stimulation on cochlear nucleus responses are not a simple passive reflection of peripheral changes but are a result of complex interactions between peripheral suppression of afferent input and collateral-mediated excitation and possibly also inhibition.

Action Potentials↗
PubMed2004

Expressed emotion versus relationship quality variables in the prediction of recurrence in bipolar patients.

BACKGROUND: The expressed emotion (EE) construct has predicted clinical outcomes in schizophrenia and depression, but few studies have been conducted with bipolar patients. Moreover, there is a particular dearth of information regarding the prediction of depressive versus manic episodes in bipolar patients. Questions also remain about the utility of EE compared to other variables (perceived criticism, relationship negativity, and chronic strain in close relationships) that more directly evaluate interpersonal stress and about specific predictions of mania or depression. METHODS: Forty-seven outpatients with bipolar I disorder participated in a 1-year longitudinal study. A close collateral of the patient completed the Five Minute Speech Sample (FMSS) to assess EE, and participants completed perceived criticism and negativity ratings of collaterals. Clinical outcomes and chronic interpersonal stress were assessed by interview at 3-month intervals. RESULTS: High EE predicted depressive, but not manic recurrence. Other variables of close interpersonal relationships were not significant predictors of recurrence. LIMITATIONS: Participants nominated collaterals, and those who did not have such a confidant were excluded. CONCLUSIONS: The FMSS was sensitive to even mild negativity by the collateral that predicted later depressive episodes. This is the first study to demonstrate polarity-specific effects of EE on the prediction of recurrence in bipolar disorder.

Adult↗
PubMed1997

Mechanisms of altered contractile responses to vasopressin and endothelin in canine coronary collateral arteries.

BACKGROUND: Mature coronary collateral arteries are hyperresponsive to vasopressin; in contrast, contractile responses of collaterals to endothelin are attenuated. Our goal was to determine the cellular mechanisms underlying these differences in reactivity using two sizes of canine collateral arteries isolated from hearts subjected to chronic coronary occlusion. METHODS AND RESULTS: Contractile responses to vasopressin (100 mmol/L) were enhanced threefold to fourfold in near-resistance (approximately 200 microns lumen diameter) and conduit (approximately 500 microns lumen diameter) collateral arteries compared with similarly sized noncollateral coronary arteries (P < .01). In contrast, contractions of both sizes of collaterals in response to endothelin (0.01 to 30 nmol/L) were smaller than responses of size-matched noncollateral arteries (P < .05). Pretreatment with either indomethacin (5 mumol/L), a cyclooxygenase inhibitor, or NG-nitro-L-arginine methyl ester (100 mumol/L), a nitric oxide synthase inhibitor, did not alter the relative responsiveness of collateral arteries to vasopressin or endothelin compared with noncollateral arteries. Vasopressin produced greater increases of intracellular free Ca2+ (measured by use of fura-2 microfluorometry and Ca(2+)-dependent 42K+ efflux) in smooth muscle of collateral arteries than in smooth muscle of noncollateral arteries (P < .05). Surprisingly, endothelin-induced increases of Ca2+ were not different in smooth muscle of collateral and noncollateral arteries (P > .05). CONCLUSIONS: We conclude that altered contractile responsiveness of collateral arteries to vasopressin and endothelin does not result from altered synthesis/release of nitric oxide or prostaglandins. Parallel enhancement of vasopressin-mediated Ca2+ and contractile responses suggests increases in vasopressin receptor number, affinity, and/or efficiency of coupling mechanisms in collateral smooth muscle. The dissociation between endothelin-induced contractile and Ca2+ responses of collaterals indicates that the mechanisms involved in increasing Ca2+ sensitivity of contractile proteins during endothelin stimulation may be altered in collateral arteries.

Animals↗