Cat scratch disease encephalopathy in an immunocompetent patient

Cat scratch disease (CSD) is typically a self-limited regional lymphadenopathy in children and young adults that is caused by Bartonella henselae. The majority of CSD cases resolve spontaneously; however, many systemic complications have been described. We report an unusual case of CSD presenting as an epitrochlear arm mass and complicated by encephalopathy. Identification of B. henselae DNA in the affected lymph node and cerebrospinal fluid confirmed the diagnosis of CSD. Systemic antibiotic therapy was administered and the patient improved without any neurological deficit.     

Histologic changes and arrhythmogenicity after discharge through transseptal catheter electrode

Ventricular tachycardia commonly arises within the intraventricular septum and successful catheter ablation of septal tachycardia might be enhanced by transseptal electrode placement. We have evaluated the safety of a transseptal ablation procedure. Arrhythmogenicity and histology were examined after high-energy capacitor discharges were delivered to an intracavitary cathode-anode pair placed on opposite sides of the interventricular septum in pentobarbital-anesthetized dogs. After two discharges of 200 or 100 J proved lethal, paired discharges of 30 or 50 J (10 dogs) or a single discharge of 100 J (four dogs) was used to induce 28 lesions. Acute rhythm changes and risk of induction of ventricular tachycardia by programmed stimulation were measures of arrhythmogenicity. Gross and histologic examination of the hearts after 20 min to 28 days allowed characterization of the evolution of lesions. The conduction system in nearby and remote locations was extensively examined in four dogs. Refractory ventricular fibrillation developed with paired shocks at 200 or 100 J. At lower energy levels, acute ventricular fibrillation occurred with 12 of 20 shocks (60%), but defibrillation was consistently achieved. After ablation, no dog had ventricular tachycardia or fibrillation induced with programmed stimulation. Matching anodal and cathodal lesions spanned the septum without perforation in 10 of 16 dogs, and the lesions were of similar histology. Each contained central areas of hemorrhage surrounded by a region of coagulation necrosis merging with normal myocytes peripherally. There was necrosis and edema without inflammation at 20 min, acute inflammatory cell infiltration at 1 to 2 days, and myocyte replacement by granulation tissue after 6 days.(ABSTRACT TRUNCATED AT 250 WORDS)     

The conduction system in transplanted hearts.

This is a serial section examination of the conduction system (CS) in six patients who died seven months, 11 months, two years four months, four years two months, 11 years, and 16 years eight months following cardiac transplantation. The heart was hypertrophied and enlarged in all. There was myocarditis of varying degree in all cases with arteriosclerosis and arteriolosclerosis. These findings were more dominant in the atria than in the ventricles. In the CS, myocarditis with fibrosis was found in all in the approaches to the sinoatrial (SA) node, the SA node, the atria, the atrioventricular (AV) node, and the bundle and bundle branches, to a varying degree. When compared with the endomyocardial biopsy findings, the autopsied cases revealed more myocarditis and fibrosis than those estimated to be present in the biopsy specimen. In summary, this study demonstrates that there are fibrotic changes in the CS with the persistence of inflammatory phenomena of the myocardium and the CS to a varying degree in transplanted hearts. This is accompanied by the ubiquitous coronary artery disease affecting not only the large coronaries but also the small vessels. The pathologic changes in and around the CS may be responsible for arrhythmias and sudden death in some cases of cardiac transplantation.     

Conduction system examination in a case of spontaneous heart block in a dog

This is a serial-section study of the conduction system in a 2-year-old boxer with electrocardiographic evidence of complete A-V block. The following findings were present: a lack of communication between the atria and the A-V node, atrophy of the A-V node, and tenuous connections between the A-V node and the A-V bundle. These were accompanied by acute degenerative changes in the conduction system. These changes are considered to be the result of arteriolosclerotic heart disease.     

Anatomic substrate for preexcitation in idiopathic myocardial hypertrophy with fibroelastosis of the left ventricle

Serial section of the conduction system and both atrioventricular (A-V) rims was performed in three patients who died with known preexcitatlon and idiopathic myocardial hypertrophy with fibroelastosis proved at autopsy. All three patients had type B preexcitation and a leftward and inferior 20 ms vector, suggesting a right free wall anomalous pathway. Patient 1 had no arrhythmia, Patient 2 died suddenly and Patient 3 had recurrent paroxysmal supraventricular tachycardia. Electrophysiologic study in Patients 1 and 3 revealed a bidirectionally conducting anomalous pathway with short refractoriness. Patient 1 had no, and Patient 3 had easily inducible A-V reentrant paroxysmal supraventricular tachycardia. Electrophysiologic study in Patient 3 revealed an anterior right free wall or anteroseptal anomalous pathway, manifested by the shortest stimulus-delta interval with pacing of the right anterior atrium. No electrophysiologic studies were performed in Patient 2.In Patient 1 serial section revealed a large right free wall anomalous pathway with myocardial disarray on the ventricular side of the anomalous pathway. In Patient 2, there were two small anomalous pathways in the right free wall. In Patient 3, no anomalous pathway was found in the right free wall; however, the right atrium was connected to the infundibular septum anterior to the membranous septum. This anomalous pathway had continuity with an anterior A-V nodal-like structure.In summary, (1) all three patients anatomically had a right-sided anomalous pathway (as predicted on electrocardlography in all three and electrophyBiologically in Patients 1 and 3). (2) In Patient 2, myocardial disarray in the Kent bundle may have prevented paroxysmal supraventricular tachycardia. (3) In Patient 3, histologic study revealed an anterior septal anomalous pathway on the right side with an anterior A-V nodal-like structure. Because the anomalous pathway did not show any A-V nodal properties, the significance of this structure is not clear. (4) The relation of the right-sided anomalous pathway to the left-sided fibroelastosis is not known.     

Duodenal necrosis as the presenting manifestation of polyarteritis nodosa

Polyarteritis nodosa involves necrotising vasculitis of small and medium-sized arteries. Multiple organ systems are involved. A non-specific and slow course of disease is common. Gastrointestinal involvement is characterised by abdominal pain, nausea and vomiting. Bowel infarction and perforation, cholecystitis and hepatic infarction are well known complications. However, bowel infarction as the presenting symptom of the disease is rare. The case of a 20-year-old male with necrosis of the duodenum heralding polyarteritis nodosa is reported. The patient made a slow recovery after extensive abdominal surgery and a stormy course. The postoperative management and treatment of polyarteritis nodosa are discussed. A high index of suspicion and prompt multidisciplinary approach are needed in order to improve survival in these rare but potentially fatal conditions. Received: 15 May 2001 / Accepted: 5 February 2002     

PDGF-A, PDGF-B, TGFbeta, and bFGF mRNA levels in patients with essential thrombocythemia treated with anagrelide

Plasmatic levels of PDGF-AB, TGFbeta1, and bFGF are increased in patients with essential thrombocythemia (ET) while intraplatelet levels are low for PDGF, normal for TGFbeta, and elevated for bFGF. To evaluate the contribution of gene expression to the dysregulated cytokine levels, we studied platelet PDGF-A, PDGF-B, TGFbeta1, and bFGF mRNA in ET patients before and during anagrelide treatment. We found decreased PDGF-A and PDGF-B, increased TGFbeta1, and normal bFGF mRNA levels. During treatment, mRNA levels remained decreased for PDGF-A, were increased for PDGF-B and normal for TGFbeta1. In untreated patients, protein expression of PDGF paralleled its mRNA levels while different patterns of RNA and protein were found for TGFbeta1 and bFGF.     

Thiocarbohydrazide-crosslinked chitosan as a bioinspired corrosion inhibitor for protection of stainless steel in 3.5% NaCl

A facile single-step synthesis was performed to cross-link chitosan with thiocarbohydrazide to yield thiocarbohydrazide-chitosan (TC-Cht) which was for the first time evaluated as an inhibitor for corrosion of stainless steel in 3.5% NaCl solution. A comprehensive electrochemical analysis employing electrochemical impedance spectroscopy (EIS), potentiodynamic polarization (PDP), and cyclic voltammetry (CV) was undertaken and showed that the TC-Cht acts by adsorption on the steel surface and exhibits mixed type behavior with predominantly cathodic nature. The adsorption of TC-Cht molecules on the surface of stainless steel followed the Langmuir isotherm. The TC-Cht showed a high inhibition efficiency of >94% at 500 mg L^?1 concentration. Surface investigation using SEM and EDX supported the inhibitor adsorption on the steel surface.