Case of spontaneous healing of occlusive dissection on percutaneous transluminal coronary angioplasty

A large pseudolumen due to dissection arose during percutaneous coronary angioplasty. The true lumen was compressed critically. However, no infarction took place because of good collaterals. During medical follow-up, the patient's angina vanished suddenly. The repeat angiography showed healing of the dissection and patency of the coronary artery.     

Altered platelet alpha 2 adrenoreceptor in acute myocardial infarction and its relation to plasma catecholamine concentrations

Changes in platelet alpha 2 adrenoreceptors and their relation to plasma catecholamine concentrations were studied in 11 patients with acute transmural myocardial infarction. A radiolabelled alpha 2 adrenoreceptor antagonist, [3H]-yohimbine, was used to assay alpha 2 adrenoreceptors on platelet membranes, and plasma catecholamine concentrations were measured by high performance liquid chromatography. The number of platelet alpha 2 adrenoreceptors, the dissociation constant, and plasma noradrenaline and adrenaline concentrations were studied 6.6 (3.3) (mean (SD)) hours after the onset of acute myocardial infarction and one month later. The mean (SD) number of adrenoreceptors increased significantly from 94.5 (50.5) fmol/mg protein immediately after infarction to 157.0 (65.7) fmol/mg protein one month later. The dissociation constant, however, did not change significantly (4.33 (1.40) nmol/l vs 4.37 (1.22) nmol/l). Raised noradrenaline (5.60 (4.37) nmol/l) and adrenaline (0.28 (0.14) nmol/l) concentrations had fallen significantly to normal values (1.21 (0.67) and 0.09 (0.05) nmol/l respectively) a month after infarction. The decrease in the number of alpha 2 adrenoreceptors soon after infarction may be beneficial because such a change will reduce the strength of various reactions to catecholamines, such as vasoconstriction.     

Osteoporosis in anorexia nervosa

Anorexia nervosa (AN) has recently become one of common disorders in adolescent girls. A chronic course of AN is related to morbidity, with one of the most serious medical complications being severe osteopenia. The prevalence of osteoporosis is estimated to be 40 % in AN during the follow up. The incidence of bone fracture in AN after the recovery of body weight is reported to be two to seven higher than that in healthy age-matched controls. Because adolescence is a critical time in terms of acquisition of peak bone mass, osteopenia during this time may be permanent. Adult woman with adolescence-onset AN has lower bone mineral density than that with adult-onset AN. In addition, bone mineral density (BMD) of AN has been shown to be influenced by several factors, including reduced body weight due to malnutrition, intake of calcium and vitamin D, and duration of estrogen deficiency. Among them, body weight is known to be the most important prognostic factor, both in a short and long period of years. Thus, medical doctor should monitor BMD in patients with AN throughout their life.     

Comparison of gastric peristalsis inhibition by scopolamine butylbromide and glucagon: evaluation by electrogastrography and analysis of heart rate variability

Background. Activation of glucagon receptors of the smooth muscle membrane suppresses gastric peristalsis. We evaluated autonomic nervous activity by two methods, electrogastrography (EGG) and analysis of heart rate variability, to compare the inhibiting effects of glucagon and scopolamine butylbromide on gastric peristalsis. Methods. Heart rate variability, EGG, and blood catecholamine levels were measured before and after administration of glucagon (G group), scopolamine butylbromide (SB group), or physiological saline (C group). Autonomic nervous function was evaluated using spectral analysis of heart rate variability, and low frequency (LF) and high frequency (HF) power; the LF/HF ratios were also determined. Results. After administration of scopolamine butylbromide, HF power, an index of parasympathetic nervous activity, decreased; and the LF/HF ratio, an index of sympathetic nervous activity, increased. In contrast, no significant change was observed in autonomic nervous activity after administration of glucagon. The peak power amplitudes of the EGG decreased significantly in the G and SB groups after intramuscular injection, but the difference between the groups was not significant. Furthermore, the dominant frequency increased significantly in the G and SB groups after injection. Serum catecholamine levels showed no significant changes after administration of scopolamine butylbromide or glucagon. Conclusions. Inhibition of gastric peristalsis by glucagon via glucagon receptors on smooth muscles did not influence autonomic nervous activity, unlike the results obtained after administration of scopolamine butylbromide. Therefore, glucagon may be safe for use with elderly patients and those with cardiopulmonary complications.     

Lowering of oxidative stress in hemodialysis patients by dialysate cleaning: in relation to arteriosclerosis

The objective of this study was to investigate changes in oxidative stress associated with the cleaning of the dialysate. Thirty-six dialysis patients were studied. Changes in soluble CD-14 (sCD-14), malondialdehyde-low-density lipoprotein (MDA-LDL), and oxidized-LDL (Ox-LDL) were monitored for 1 year before and 1 year after dialysate cleaning. The mean endotoxin (ET) level in the dialysate had previously been confirmed to decrease from 39.0 EU/L to an undetectable level after the cleaning. The mean levels of sCD-14, MDA-LDL, and Ox-LDL decreased significantly after the cleaning (sCD-14, P < 0.0001; MDA-LDL, P < 0.001; Ox-LDL, P < 0.001). One year after the cleaning, six cases still showed high levels of MDA-LDL and Ox-LDL. Cardiovascular events occurred in four of those six cases within 2.8 years after the cleaning. These four patients suffered from strong oxidative stress during dialysis, even after the cleaning. We therefore concluded that high levels of MDA-LDL and Ox-LDL are improved in dialysis patients by cleaning of the dialysate. These results indicate that even a dialysate containing 50 EU/L or less ET may stimulate monocytes and cause oxidative stress. They also suggest that even low levels of ET may aggravate arteriosclerosis in dialysis patients. Thus, in order to prevent cardiovascular events in dialysis patients, it is necessary to purify the dialysate.     

Ventricular septal rupture masquerading as coronary perforation during intervention for acute myocardial infarction

Ventricular septal rupture is a serious complication of acute myocardial infarction. We experienced a case of septal rupture immediately after primary angioplasty with thrombolysis, whose angiographic findings were similar to those of coronary perforation. The progression of septal rupture was delineated by the serial angiograms. Catheter Cardiovasc Interv 2004;62:466–470. © 2004 Wiley‐Liss, Inc.     

Ephrin-B2 controls PDGFRβ internalization and signaling

B-class ephrins, ligands for EphB receptor tyrosine kinases, are critical regulators of growth and patterning processes in many organs and species. In the endothelium of the developing vasculature, ephrin-B2 controls endothelial sprouting and proliferation, which has been linked to vascular endothelial growth factor (VEGF) receptor endocytosis and signaling. Ephrin-B2 also has essential roles in supporting mural cells (namely, pericytes and vascular smooth muscle cells [VSMCs]), but the underlying mechanism is not understood. Here, we show that ephrin-B2 controls platelet-derived growth factor receptor β (PDGFRβ) distribution in the VSMC plasma membrane, endocytosis, and signaling in a fashion that is highly distinct from its role in the endothelium. Absence of ephrin-B2 in cultured VSMCs led to the redistribution of PDGFRβ from caveolin-positive to clathrin-associated membrane fractions, enhanced PDGF-B-induced PDGFRβ internalization, and augmented downstream mitogen-activated protein (MAP) kinase and c-Jun N-terminal kinase (JNK) activation but impaired Tiam1–Rac1 signaling and proliferation. Accordingly, mutant mice lacking ephrin-B2 expression in vascular smooth muscle developed vessel wall defects and aortic aneurysms, which were associated with impaired Tiam1 expression and excessive activation of MAP kinase and JNK. Our results establish that ephrin-B2 is an important regulator of PDGFRβ endocytosis and thereby acts as a molecular switch controlling the downstream signaling activity of this receptor in mural cells.     

Ultra-Early Induction of General Anesthesia for Reducing Rebleeding Rates in Patients with Aneurysmal Subarachnoid Hemorrhage

ObjectiveRebleeding of aneurysmal subarachnoid hemorrhage (aSAH) is one of the significant risk factors for poor clinical outcome. The rebleeding risk is the highest during the acute phase with an approximate rebleeding rate of 9-17% within the first 24 h. Theoretically, general anesthesia can stabilize a patient's vital signs; however, its effectiveness as initial management for preventing post-aSAH rebleeding remains unclear. The purpose of this study was to determine the feasibility and safety of ultra-early general anesthesia induction for reducing the rebleeding rates among patients with aSAH.Materials and methodsWe retrospectively evaluated patients with aSAH who were admitted to our department between January 2013 and December 2019. All the patients underwent ultra-early general anesthesia induction as initial management regardless of their severity. We evaluated the rebleeding rate before definitive treatment, factors influencing rebleeding, and general anesthesia complications.ResultsWe included 191 patients with two-third of them having a poor clinical grade (World Federation of Neurological Society [WFNS] grade IV or V). The median duration from admission to general anesthesia induction was 22 min. Rebleeding before definitive treatment occurred in nine patients (4.7%). There were significant differences in the Glasgow Coma Scale score (p = 0.047), WFNS grade (p = 0.02), and dissecting aneurysm (p <0.001) between the rebleeding and non-rebleeding patients. There were no cases of unsuccessful tracheal intubation or rebleeding during general anesthesia induction.ConclusionUltra-early general anesthesia induction could be performed safely in patients with aSAH, regardless of the WFNS grade; moreover, it resulted in lower rebleeding rate than that reported in previous epidemiological reports.