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.     

A case of cystic lymphangioma of the liver

Here is a case report about a cystic lymphangioma of the liver, a rare benign tumor, extremely difficult to diagnose with certainty in spite of the wide range of examinations today available. Surgical intervention is still the most important means to achieve the final diagnosis. The authors also provide a discussion about the pathogenesis and the clinical manifestation of the disease.     

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.      

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.      

Effect of chronic morphine on plasma and brain beta endorphin and methionine enkephalin in pregnant rats and in their fetuses or newborn

Normal or pregnant rats were treated orally for 21 days or throughout pregnancy with water or increasing doses of morphine and killed on days 7, 14, and 21 of pregnancy and 1 day post partum. At these time intervals, plasma, pituitary, and hypothalamic concentrations of beta-endorphin and methionine enkephalin were measured in normal and pregnant rats. Moreover, pituitary and hypothalamic concentrations of the two peptides were also measured in fetuses and newborn. Plasma beta-endorphin and methionine enkephalin increased significantly during pregnancy without any specific effect of morphine. Pituitary concentrations of beta-endorphin were not modified either by pregnancy or morphine treatment, while methionine enkephalin concentrations increased on days 7 and 11 of pregnancy, in both water- and morphine-treated rats. The pattern of the two peptides in the hypothalamus is completely superimposable to the one present in the pituitary with the exception of an increase of beta-endorphin on day 21 of pregnancy, which is more evident in control animals. Consistently with our observations in human newborn and the neurological dysfunctions we observed in them, the concentrations of both the peptides are significantly increased in the hypothalamus of fetuses and newborn of morphine-treated mothers, while in the pituitary only beta-endorphin concentrations are increased.     

Effects of a new metabolic modulator, ranolazine, on exercise tolerance in angina pectoris patients treated with beta-blocker or diltiazem.

Ranolazine (RS 43285) is a new piperazine derivative with anti-ischemic properties attributed to a modulation of myocardial metabolism. Its antianginal action was assessed in 104 patients recruited in a double-blind, crossover, randomized study comparing placebo with a single dose of ranolazine (10, 60, 120, and 240 mg). All patients had chronic stable angina pectoris and remained symptomatic (at least 0.1 mV ST-segment depression and angina during prestudy exercise testing) despite treatment with a beta-blocker or with diltiazem. No significant effects of ranolazine on exercise duration or time to angina were observed after the dose of 10, 60, and 120 mg. After the 240 mg dose, however, significant improvement in exercise duration (+13.1% in the combined group, two-tailed p = 0.002; +14.3% in the beta-blocker group, p = 0.009; +11.9% in the diltiazem group, p = 0.06), in time to angina (+56.8 s, p = 0.008), and in time to 1 mm ST-segment depression was observed. The cumulative proportion of patients who improved their time to angina by at least 30 s above placebo were 25, 42, 50, and 72% with the doses of 10, 60, 120, and 240 mg, respectively. Sixty-seven percent of the patients with ranolazine plasma levels above 500 ng/ml improved their time to angina against 40% at plasma levels below 500 ng/ml and summed ST-segment depression during exercise and recovery was also significantly reduced at these plasma concentrations. Both heart rate and arterial pressure at rest and at peak exercise were unchanged after ranolazine, 240 mg.(ABSTRACT TRUNCATED AT 250 WORDS)