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.      

Enhancing effect of staurosporine on NO production in rat peritoneal macrophages via a protein kinase C-independent mechanism.

Staurosporine (3-100 nM), frequently used as a protein kinase C (PKC) inhibitor, increased accumulation of nitrite in the culture medium of rat peritoneal macrophages up to 6 times above the control level. Moreover, when used in combination with the stable analogue of cyclic AMP, dibutyrylcyclic AMP (db cyclic AMP; 0.1 mM), and/or a cytokine, tumour necrosis factor-alpha (TNF alpha; 100 u ml-1), staurosporine synergistically potentiated, up to 30 times, nitrite accumulation. On the other hand, the other PKC inhibitors, calphostin C and H-7 (10 nM-10 microM) were not effective under the same conditions. The staurosporine-induced nitrite accumulation, in both the presence and the absence of TNF alpha and/or db cyclic AMP was effectively inhibited by the protein synthesis inhibitor, cycloheximide, or by the nitric oxide (NO) synthesis inhibitor, NG-monomethyl-L-arginine (L-NMMA). Thus our data suggest that staurosporine may enhance NO production in macrophages via intracellular mechanisms unrelated to the PKC inhibition.     

Cancer of remnant stomach following gastric surgery for benign conditions

Eighteen patients received gastrectomy for primary cancer of the gastric remnant were studied clinico-histopathologically. Gastric ulcer had been the most common condition requiring previous gastric surgery, and Billroth II resection had been the most often employed procedure. The cancer of the gastric remnant was in an advanced stage in all patients. Tumors were detected in the sutured or anastomosed region (especially the latter) of the remnant stomach in a great majority of the patients studied. In spite of combined resection of the adjacent organs, such as spleen, pancreas and colon in most patients, curative resection could be done in only a half of them and the prognosis was poor in general. These observations seem to stress the importance of following up gastrectomized patients periodically and precautiously by endoscopic examination with multiple biopsy, because early detection of cancer of remnant stomach may lead to improvements in therapeutic results.     

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.