Intra- and inter-observer reliability of Cobb angle measurements in patients with adolescent idiopathic scoliosis.

PURPOSE: The Cobb angle method is used to determine the severity of scoliosis. Therapeutic decisions for adolescent idiopathic scoliosis (AIS) are guided by the Cobb angle. Therefore, high reliability is crucial. The objective of this study was to determine the intra- and inter-observer reliability of the digital Cobb angle measurements and the definition of end vertebrae in patients with AIS. Moreover, the influence of the observer's medical specialty and experience on Cobb angle measurement was evaluated. METHODS: Intra- and inter-observer reliability of the digital Cobb angle and end vertebrae is assessed in postero-anterior radiographs of 39 patients with AIS. Measurements were performed blinded and twice by six observers, with a two to 3 week interval. Intra- and inter-observer reliability was analysed by means of intraclass correlation coefficients (ICC). RESULTS: Both intra- and inter-observer reliability analyses resulted in ICC's higher than 0.864 for the Cobb angle and definition of end vertebrae. In addition, for the observer's experience and medical specialty group the inter-observer ICC's were higher than 0.984. The average inter-observer variability for the Cobb angle were 3°, and 1.1-1.6 levels for the cranial and caudal end vertebrae selection. The variability in measured Cobb angle was 1° for the experience group and 2° for the medical specialty group. Cronbach's alpha varied from 0.990 to 0.996. Bland-Altman plots showed moderate variation with a few outliers. CONCLUSIONS: The digital Cobb angle measurement as well as the definition of end vertebrae show excellent reliability. According to our results, medical specialty and experience do not affect Cobb angle measurements and definition of end vertebrae.

Survey of fumonisin production by Fusarium species.

Fumonisins B1 (FB1) and B2 (FB2), two structurally related mycotoxins with cancer-promoting activity, were recently isolated from corn cultures of Fusarium moniliforme MRC 826. These toxins have been reported to be produced also by isolates of F. proliferatum. Contamination of foods and feeds by F. moniliforme has been associated with human esophageal cancer risk, and FB1 has been shown to be the causative agent of the neurotoxic disease leukoencephalomalacia in horses. Because of the toxicological importance of the fumonisins, the potential to produce FB1 and FB2 was determined in a study of 40 toxic Fusarium isolates representing 27 taxa in 9 of the 12 sections of Fusarium, as well as two recently described species not yet classified into sections. With the exception of one isolate of F. nygamai, fumonisin production was restricted to isolates of F. moniliforme and F. proliferatum, in the section Liseola. The F. nygamai isolate produced 605 micrograms of FB1 g-1 and 530 micrograms of FB2 g-1, and the identity of the toxins was confirmed by capillary gas chromatography-mass spectrometry. This is the first report of the production of the fumonisins by F. nygamai.

Production of mycotoxins by selected Fusarium graminearum and F. crookwellense isolates.

Corn cultures (five isolates each of Fusarium graminearum Group 1 from wheat crowns, Group 2 from scabby wheat grains and from ear rot of corn and five isolates of F. crookwellense) were screened for their ability to produce deoxynivalenol (DON), nivalenol (NIV), fusarenon-x (FUS-X) and zearalenone (ZEA). Nine of the ten F. graminearum isolates from wheat produced DON (5-165 micrograms g-1) but none produced either NIV or FUS-X. Conversely, 3/5 and 2/5 of the F. graminearum isolates from corn produced NIV (5-40 micrograms g-1) and FUS-X (5-7 micrograms g-1), respectively, while none produced DON. All but one of the F. graminearum isolates produced ZEA (2-1160 micrograms g-1). None of the F. crookwellense isolates produced DON, but 5/5 and 4/5 produced NIV (6-170 micrograms g-1) and FUS-X (3-90 micrograms g-1), respectively, and all produced ZEA (605-1030 micrograms g-1). The results confirmed previous findings on the presence of two distinct F. graminearum chemotypes.

Dihydropyridine calcium antagonists depress the amplitude of the plasma melatonin cycle in baboons.

An investigation into the effects of verapamil and some dihydropyridine derivatives on plasma melatonin levels was undertaken in baboons. In a number of separate experiments, groups of young male chacma baboons (mean body weight 13 kg) received intraperitoneal injections of the drugs, under ketamine anaesthesia, roughly 30 minutes prior to the following time points: 1200, 1800, 0000, 0200, 0600 and 1200 h. Lights went off at 1800 h and came on at 0600 h. The drugs used, and their respective dosages (expressed per kg body mass), were verapamil up to 4 mg/kg, nifedipine at 0.2 mg/kg, nitrendipine at 0.5 mg/kg and nisoldipine at 0.1 mg/kg. Blood samples, taken at the said time points, were assayed for melatonin. The nighttime peak of the plasma melatonin cycle was significantly depressed by all three dihydropyridine calcium antagonists (up to 40%), while verapamil, even at the relatively high total dose of 24 mg/kg per day, had no significant effect on the circulating plasma melatonin levels.

Cardiac substances that influence blood-pressure. II. Potent pressor activity in rat and rabbit atrial muscle.

In addition to their natriuretic, diuretic and vasodilator activities, freshly prepared aqueous extracts of either rat or rabbit atrial myocardium were shown to elicit significant increases in the blood-pressure of anaesthetized rats. Small aliquots (0.05 ml) intravenously administered caused a transient rise in mean arterial blood-pressure of up to 20%. Slow infusion of 0.4 ml right atrial extract (corresponding to about one half of a rabbit right atrial lobe) during 90 seconds caused the expected natriuresis and diuresis, together with a sustained elevation in arterial blood-pressure (ca 25%) that returned to normal within 3 minutes. This potent pressor activity could not be detected in ventricular extracts. It was furthermore readily separable from the natriuretic peptides and catecholamines by ultrafiltration. The atrial pressor factor is a small proteolytically unstable molecule (300-1000 dalton).

Cardiac substances that influence blood-pressure. I. Identification of the agent that lowers blood-pressure in anaesthetized rats.

Extracts of the atrium of the mammalian heart contain a natriuretic factor which may be associated with the atrium-specific granules. It has often been observed that the intravenous injection of a crude atrial extract into anaesthetized rats, causes a transient decrease in blood-pressure. In rabbits, this activity is present in stored aqueous extracts prepared from both atrial and ventricular tissue. The hypotensive activity, which can be readily separated from the natriuretic factor, is mainly due to the presence of adenosine and its derivatives, of which 5'-adenosine monophosphate is the major contributor. However, an extract from rabbit atrial muscle, carefully prepared under stringent conditions, caused a rapid and striking increase in blood-pressure, an activity that could not be detected in ventricular tissue.

Arginine vasotocin (AVT), an alleged hormone of the mammalian pineal gland.

Arginine vasotocin has been proposed as a hormone of the mammalian pineal gland. This claim is largely based on biological and immunological results, although some chemical evidence has also been provided. Yet, more and more researchers have recently disclaimed the presence of this nonapeptide in mammalian tissue. The currently available evidence is critically reviewed exposing the dispute as a real one urgently requiring final settlement.