Intracranial circulation: pulse-sequence considerations in three- dimensional (volume) MR angiography

The technique and feasibility of magnetic resonance (MR) angiography of intracranial vessels were studied in 35 healthy volunteers. Variations in image orientation, repetition time (TR), and flip angle were evaluated to determine their effects on flow-related enhancement. Gradient modifications--including echo time (TE), motion compensation, bandwidth, and field of view--were also studied in an effort to reduce motion-induced phase shifts. Results indicated that a FISP (fast imaging with steady precession) sequence with a TR of 50 msec, TE of 15 msec, velocity compensation in the read and section-select directions, acceleration compensation in the read direction, anisotropic volume, and a 1.25-mm partition thickness produced three-dimensional angiographic MR images that were accurate and reproducible in the depiction of the major intracranial vessels. Difficulties with field of view, persistent signal void secondary to higher-order motion, and spatial resolution remain major problems requiring additional study.     

Maxillary sinusitis in adults: an evaluation of placebo-controlled double-blind trials

BACKGROUND: In general practice, acute sinusitis is frequently diagnosed and treated with antibiotics. OBJECTIVE: This study aimed to determine the evidence for the effectiveness of antibiotic treatment in acute maxillary sinusitis in adults by assessing the methodological quality of placebo-controlled double-blind randomized trials. METHOD: An evaluation by four raters through a 35-item scoring-scale for internal and external validity of all placebo-controlled double-blind randomized trials on acute sinusitis found between January 1966 and July 1996. RESULTS: Eighty-five trials were excluded because they were not placebo-controlled, double-blind, randomized, or were carried out in patients with chronic sinusitis or in children. The three remaining trials were performed in different populations (one in general practice) between 1973 and 1978. Only one study claimed superiority of antibiotic treatment. Different inclusion criteria and major outcome measures were used by the authors. The reliability of major outcome events was reported poorly or not at all and in two studies outcome measures were clinically inappropriate. The studies scored 30-62% of the maximum attainable score for internal validity and 10-20% for external validity. CONCLUSION: The effectiveness of antibiotic treatment in acute maxillary sinusitis in a general practice population is not based sufficiently on evidence.      

Aneurysm of the azygos pericallosal artery. One case.

The Authors describe a case of aneurysmal rupture of the azygos pericallosal artery, a variant of the anterior cerebral artery. The association between aneurysm and this anatomical anomaly is of interest because of its rarity and clinical-therapeutic implications.     

4,5-Dianilinophthalimide: a protein-tyrosine kinase inhibitor with selectivity for the epidermal growth factor receptor signal transduction pathway and potent in vivo antitumor activity.

Deregulated signal transduction via the epidermal growth factor receptor (EGF-R) family of protein-tyrosine kinase growth factor receptors is associated with proliferative diseases. We describe a class of compounds (4,5-dianilinophthalimides) that inhibit the EGF-R protein-tyrosine kinase in vitro with high selectivity. In cells, 4,5-dianilinophthalmide selectively inhibited both ligand-induced EGF-R and p185c-erbB2 autophosphorylation and c-fos mRNA induction. Antitumor activity could be demonstrated in vivo against xenografts of the A431 and SK-OV-3 tumors, which overexpress the EGF-R and p185c-erbB2, respectively. In contrast, a platelet-derived growth factor-driven tumor was not inhibited by 4,5-dianilinophthalimide, which is compatible with its cellular selectivity and hypothesized mechanism of action. No overt cumulative toxicity was observed during treatment even though high efficacy was observed, indicating a good therapeutic window. 4,5-Dianilinophthalimides may offer therapeutic agents for the treatment of hyperproliferative diseases that overexpress EGF-R family protein-tyrosine kinases or their ligands.     

Convergence of occipital nerve and superior sagittal sinus input in the cervical spinal cord of the cat

Co-existence of facial and occipital pain may occur in occipital neuralgia, migraine and cluster headache; suggesting convergence of trigeminal and cervical afferents. Such convergence has been shown in humans and other animals, but the site and extent of this are uncertain. In anaesthetized adult cats, the superior sagittal sinus and occipital nerve were stimulated electrically, and extracellular recordings made in the dorsolateral area of the upper cervical cord using glass-coated tungsten electrodes. Of 49 units in 10 cats, 33 (67%) had input from the superior sagittal sinus and the occipital nerve. Thirteen (27%) had superior sagittal sinus input and 3 (6%) had occipital nerve input. Convergent receptive fields were identified mechanically in 7 units. These experiments in cats show convergent input from occipital nerve and superior sagittal sinus on dorsolateral area units in two-thirds of cases studied. This experimental site of trigeminocervical convergence may relate to referral of pain in occipital neuralgia and other headaches.     

Nonsteroidal anti-inflammatory drugs (NSAIDs) and the kidney

In patients with PG-dependent renal function, NSAID administration constantly reduces GFR and RBF in a dose-dependent fashion. In this situation, the risk of overt acute renal failure is high and should be taken into proper account. In contrast, the incidence of NSAID-related renal structural alterations appears to be very low, yet the absolute number of patients may be significant considering the wide use of such drugs. Concerning the antiproteinuric effect of NSAIDs, the unfavourable ratio risk/benefit does not seem to support their indication in proteinuric nephropathies. The development of PGHS-2 selective inhibitors is promising, and may open new therapeutical strategies in the treatment of the progression of renal disease.      

Spontaneous arterio-venous fistulae of the vertebral artery. Diagnostic and therapeutic considerations

Spontaneous arterio-venous fistulae of the vertebral artery are rare. These lesions mainly affect the upper cervical area, and are usually asymptomatic, or may present as small, often pulsatile, cervical masses with vascular murmurs. The authors report on two cases in which the presumptive diagnosis, suggested by venous digital subtraction angiography, was then confirmed by selective angiography. In both cases an intravascular approach with detachable balloons and particulate substances was carried out, with good anatomical and functional results. Problems related to diagnosis, pathophysiology of symptoms, indications for treatment and embolization techniques are discussed.