Recognizable phenotypes associated with intracranial calcification

Aim In this observational study, we adopted a systematic approach to the radiological phenotyping of disorders associated with intracranial calcification, with the aim of determining if characteristic patterns could be defined as an aid to the future diagnosis of known conditions and the identification of new disorders. Method A cranial imaging‐based scoring system was devised using both computed tomography and magnetic resonance imaging data. Patients were grouped into diagnostic categories where a definitive molecular diagnosis was known, or where the clinical and radiological features suggested a specific diagnosis. For patients in whom the diagnosis was unknown, subgroups were defined according to shared radiological features. Results Data on 244 scans from 119 patients were analysed. A specific diagnosis was available for 59 patients (31males, 28 females; median age 50mo, range 1wk to 54y). These were as follows (number of patients in brackets): Aicardi–Goutières syndrome (33), cerebroretinal microangiopathy with calcification and cysts (10), band‐like calcification with simplified gyration and polymicrogyria (6), COL4A1‐related disease (3), Degos disease (2), Krabbe disease (2), Alexander disease (1), mitochondrial disease (1), and tetrasomy 15 (1). In 60 patients the aetiology was unknown. Within this group, subsets demonstrating shared characteristics suggestive of a specific calcification phenotype could be identified. Interpretation This study confirms the value of a systematic approach to radiological phenotyping of disorders associated with intracranial calcification.     

Autonomic Nervous System Activity During Tilt Testing in Syncopal Patients, Estimated by Power Spectral Analysis of Heart Rate Variability

Spectral analysis of heart rate variability (HRV) was used to assess changes in autonomic function before and during postural tilt in 28 syncopal patients: 14 (group A) with positive and 14 (group B) with negative tilting test, and 14 normal controls (group C). Frequency-domain measurements of the high (HF) and low (LF) frequency bands and the ratio LF/HF were derived from Holter recordings, computed by Fast Fourier analysis for 4-minute intervals immediately before tilt testing, immediately after tilting, and just before the end of the test. In group A, the mean values of LF and HF decreased slightly in response to tilting while the LF/HF ratio increased, though these changes were not statistically significant. All parameters showed a statistically significant increase just before the onset of syncope. In group B, there were no significant changes in the parameters measured throughout the test. In group C. there was an increase in the LF and LF/HF ratio and a decrease in the HF immediately after tilting. There were no further significant changes in any of the parameters during the test. Syncopal patients have a different pattern of response to the orthostatic stimulus, in that they do not show the increase in sympathetic tone observed in normal individuals immediately after tilting. In the patients with a positive tilt test, there is a shift in the balance of ANS activity towards the sympathetic system shortly before the onset of syncope. (PACE 1997; 20[Pt. I]:1332-1341)     

Hydatid cyst of the seminal vesicle

We present a rare case of a hydatid cyst involving the seminal vesicle of a 48-year-old man. Urinary retention was the initial symptom. Both imaging and clinical evaluation revealed a substantial retrovesical cystic mass. The histopathological report was 'hydatid cyst of the seminal vesicle'.     

Synthesis of potent agonists of Substance P by replacement of Met11 with Glu(OBzl) and N-terminal glutamine with Glp of the C-terminal hexapeptide and heptapeptide of Substance P

The analogues [Glp⁶,Glu(OBzl)¹¹]SP_(6-11) and [Glp⁵,Glu(OBzl)¹¹]SP_(5-11)) of the C-terminal hexapeptide and heptapeptide of Substance P have been synthesized by conventional solution methods. In each analogue the N-terminal glutamine has been replaced by pyroglutamic acid, while the COOCH₂C₆H₅ ester group has replaced the SCH₃ group of the Met¹¹ side chain. The in vitro activity of both analogues has been determined on three biological preparations: guinea pig ileum (GPI), rat vas deferens (RVD) and rat portal vein (RPV). The results showed that both analogues are highly potent and selective agonists on GPI through the NK-1 receptor. They are more potent than SP itself, with 1.54 and 1.25 respective values of relative potency on GPI. Their selectivity has been studied by utilizing atropine-treated guinea pig ileum (GPI + At). The analogues showed low activity on RVD and RPV tissues, which represent NK-2 and NK-3 monoreceptor assay, respectively. © Munksgaard 1995.     

Authorship ethics in the radiological sciences

The written communication of new ideas and current developments is a crucial part of the progress of radiological sciences. Research results cannot be incorporated into the body of scientific knowledge, unless they are published. In radiology, questions on authorship ethics have received limited attention. Among the topics discussed in this article are the incentives that stimulate radiologists to write and the obstacles to successful authorship. Practices causing concern to editors, authors and readers are examined, such as the excessive growth through recent years in the numbers of authors per paper, unjustified co-authorships, wasteful publication practices and fraudulent research. The relationship between the abuses of authorship and the pressure exerted on researchers to publish is exemplified. Further issues addressed include the responsibilities of authors, the proposed principles for authorship, the determination of the sequence of authors in multi-authored papers and the concept of publication credit. The editor's role in preventing unethical authorship is examined and emphasis is placed on the proposals that have been made to achieve the required reforms by eradicating the publish or perish mentality.     

Is There Increased Sympathetic Activity in Patients with Mitral Valve Prolapse?

The aim of this study was to investigate autonomic nervous system tone in patients with mitral valve prolapse (MVP). Heart rate variability (HRV) was assessed from 24-hour ambulatory Holter recordings in 28 patients with primary MVP and in 28 age and sex matched normal control subjects in a drug-free state. Sixteen of the MVP patients were symptomatic and 12 asymptomatic. Spectral HRV was calculated in terms of low (LF: 0.06–0.15 Hz) and high (HF: 0.15–0.40 Hz) frequency components using fast Fourier transform analysis, and the ratio LF/HF was calculated. Spectral analysis of HRV showed that the MVP patients, taken as a single group, had lower HF and LF and a higher LF/HF ratio than the controls. No significant difference in HRV was found between the 16 symptomatic and the 12 asymptomatic patients, but the symptomatic patients had a significantly higher LF/HF ratio than the controls. Our observations suggest that, during normal daily activities, patients with MVP experience a significant deviation in autonomic nervous system tone with predominance of the sympathetic branch. This predominance is more marked in symptomatic patients.     

Drug‐Induced Brugada Syndrome by Noncardiac Agents

Drug‐induced Brugada syndrome (BrS) represents a great challenge for the prescribing clinicians as well as for those involved in the development of novel pharmaceuticals and in the regulatory bodies responsible with monitoring drug safety. Apart from well‐known cardiac agents (mainly Class I antiarrhythmics), an increasing number of noncardiac agents, including psychotropic and anesthetic drugs, have been shown to induce the characteristic Brugada electrocardiogram pattern predisposing to fatal ventricular arrhythmias. Up to now, both repolarization and depolarization abnormalities are thought to be related to the development of ventricular fibrillation in BrS patients. This review highlights the mechanisms and the noncardiac medical agents that unmask a genetic predisposition to BrS.