Low-dose aspirin in patients recovering from myocardial infarction. Evidence for a selective inhibition of thromboxane-related platelet function

The adequacy, selectivity and long-term persistence of inhibitionin cyclooxygenase-dependent platelet function by a daily low-dose(0.45 mg kg^–1 day^–1) aspirin treatment have beenevaluated in 15 patients after a recent (less than 17 days)acute myocardial infarction. Serum thromboxane (TX) B₂, an indexof platelet TXA₂ production, was decreased by 94–98% (P<0.001)by aspirin, while urinary excretion of 6-keto-prostaglandinF^la, as an index of extraplatelet cyclooxygenase activity, remainedunchanged. Compared to placebo, aspirin induced a persistentincrease in bleeding time (% difference 45.6±21.4, mean± SD) and a decrease in platelet aggregation by ADP,epinephrine, collagen and arachidonic acid. No tendency towardsan attenuation of the effects was apparent for the period ofaspirin administration (4 weeks). Aspirin 0.45 mg kg^–1 day^–1 is adequate and selectivein the long-term inhibition of TX-related platelet functionin patients after acute myocardial infarction. The clinicaleffectiveness of such a regimen remains to be proven in clinicaltrials.     

Psychological status of men with haemophilia and HIV infection: two-year follow-up

This study aimed to assess the psychological status of men with haemophilia and HIV infection and to monitor changes in psychlogical status over time, in order to evaluate the need for psychological support. The study included 24 HIV seropositive men and a control group of 21 HIV seronegative men who attended the Haemophilia Centre in Bari (Italy). Subjects underwent psychological tests (STAl-Y: State and Trait Anxiety Inventory; SDS: Self-Rating Depression Scale) and completed a questionnaire on the emotional impact of AIDS. Assessment was repeated at 6-monthly intervals over a 2-year period. Contrary to expectation, HIV seronegative men with haemophilia had worse anxiety and depression scores, reported more confusion and fear, and had more reluctance towards the use of blood products (despite their present safety) than HIV seropositives. Possible reasons for these findings are considered, and their implications for clinical practice discussed.     

Enzymatic methyl esterification of a deamidated form of mouse epidermal growth factor

The enzyme S-adenosylmethionine:protein carboxyl-O-methyl-transferase, type II (EC2.1.1.77; PCMT) from eukaryotes methyl esterifies peptides containing isoAsp residues, which can arise from spontaneous deamidation of labile Asn residues. We report here a study on in vitro methyl esterification of mouse EGF by bovine brain PCMT. This peptide contains two Asn in the sequences Asn¹-Ser² and Asn¹⁶-Gly¹⁷. It is known from the literature that the presence of a small residue on the carboxyl side of asparaginyl makes this residue susceptible to deamidation through the spontaneous formation of a succinimide intermediate. Therefore EGF was incubated under deamidating conditions (pH9.0, 37° for 48 h) and the extent of deamidation monitored by enzymatically measuring the NH₃ produced during the alkali treatment: a release of 0.80 mol NH₃/mol EGF was calculated. The alkali-treated EGF, analyzed by anion-exchange chromatography, shows two major components identified as native EGF (nEGF) and its deamidated form (dEGF). When incubated in the presence of purified PCMT neither nEGF nor dEGF showed any methyl accepting capability. Since it is known that the three-dimensional structure of a protein may hinder the methyl esterification of a potential ethyl accepting site, dEGF was unfolded by reducing and alkylating the intrachain disulfide bridges. Only a slight increase in the methyl accepting capability could be observed. Conversely, when EGF was deamidated after its unfolding, the resulting protein was stoichiometrically methylated by PCMT, presumably at level of isoAsp¹⁶. Our findings strongly suggest that the three-dimensional structure of a protein is a major specificity determinant for both deamidation and methyl esterification processes.     

A Case of Atrial Tachycardia Treated with Ivabradine as Bridge to Ablation

Ivabradine is indicated in cardiac failure and ischemia to reduce sinus rate by inhibition of the pacemaker I(f) current in sinoatrial node. We report a case of an 18‐year‐old woman with left atrial tachyarrhythmia resistant to several antiarrhythmic drugs and to electric cardioversion who responded only to ivabradine, which significantly reduced heart rate without abolishing the arrhythmia itself. An ectopic focus in the ostium of left pulmonary veins was found and the patient was successfully ablated. We suggest that ivabradine might be therefore useful in the treatment of supraventricular tachyarrhythmias due to an enhanced automaticity.     

Melanoacanthoma Simulating Pigmented Spitz Nevus: an Unusual Dermoscopy Pitfall

BACKGROUND: The starburst pattern is the dermoscopic hallmark of pigmented Spitz nevus, although it has been rarely observed in melanoma as well. OBJECTIVE: To describe a case of melanoacanthoma simulating pigmented Spitz nevus. MATERIAL AND METHODS: Clinical, dermoscopic, and histopathologic examinations were performed for the occurrence of a 4-mm pigmented skin lesion on the hip of a 38-year-old Caucasian woman. RESULTS: Dermoscopy examination of the lesion disclosed a stereotypical starburst pattern characterized by pigmented streaks symmetrically distributed at the periphery. A preoperative diagnosis of pigmented Spitz nevus was made, and the lesion was excised. However, subsequent histopathologic examination revealed a melanoacanthoma. CONCLUSION: The starburst pattern, although diagnostic for pigmented Spitz nevus, can be rarely observed in other benign or malignant pigmented skin lesions. Accordingly, all lesions in adults exhibiting a starburst pattern or other spitzoid features should be excised for histopathologic evaluation.     

Immunohistochemical evidence suggests intrinsic regulatory activity of human eccrine sweat glands

Immunohistochemistry of normal eccrine sweat glands was performed on paraffin sections of human skin. Immunoreactivity (ir) for neuron specific enolase, S100 protein (S100), regulatory peptides, nitric oxide synthase type I (NOS-I) and choline-acetyltransferase (ChAT) was found in small nerve bundles close to sweat glands. In the glands, secretory cells were labelled with anticytokeratin antibody. Using antibodies to S100, calcitonin gene-related peptide (CGRP) and substance P (SP) a specific distribution pattern was found in secretory cells. Granulated (dark) and parietal (clear) cells were immunopositive for CGRP, and S100 and SP, respectively. Immunoreactivity was diffuse in the cytoplasm for CGRP and S100, and peripheral for SP. Myoepithelial cells were not labelled. Electron microscopy revealed electron dense granules, probably containing peptide, in granulated cells. Using antibodies to NOS-I and ChAT, ir was exclusively found in myoepithelial cells. Immunoreactivity for the atrial natriuretic peptide was absent in sweat glands. These results provide evidence for the presence of both regulatory peptides involved in vasodilation and key enzymes for the synthesis of nitric oxide and acetylcholine in the secretory coil of human sweat glands. It is suggested that human sweat glands are capable of some intrinsic regulation in addition to that carried out by their nerve supply.