Color and spectral analysis of daylight in southern Europe

We have analyzed the colorimetric and spectral characteristics of 2600 daylight spectra (global spectral irradiances on a horizontal surface) measured for all sky states during a 2-year period at Granada, Spain. We describe in detail the chromaticity coordinates, correlated color temperatures (CCT), luminous efficacies, and relative UV and IR contents of Granada daylight. The chromaticity coordinates of Granada daylight lie far above the CIE locus at high CCTs (>9,000 K), and a CCT of 5,700 K best typifies this daylight. Our principal-components analysis shows that Granada daylight spectra can be adequately represented by using six-dimensional linear models in the visible, whereas seven-dimensional models are required if we include the UV or near-IR. Yet on average only three-dimensional models are needed to reconstruct spectra that are colorimetrically indistinguishable from the original spectra.

Pteridium aquilinum (bracken fern) toxicity in cattle in the humid Chaco of Tarija, Bolivia

We studied the toxicity caused by chronic ingestion of Pteridium aquilinum (bracken) in cattle in the humid Chaco of Tarija, Bolivia. Bovine enzootic haematuria (BEH) and Carcinoma of the esophagus (CE) affected the herds. Sick animals showed caquexia, anemia, leucopenia and urine that turned from pink to intense red color with the presence of blood clots. Cattle grazed in the humid forests of the mountains where P aquilinum represented more than 50% of the plants. P aquilinum var arachnoideum and P aquilinum var Caudatum were present. Toxic norsesquiterpene, ptaquiloside, was identified in both varieties. Carcinomas were in the urinary bladders and esophagus of 100% and 50% of the cattle, respectively. Control of the intoxication could be difficult due to geographic characteristics of this Bolivian region.

Scapular neck fracture--the influence of permanent malalignment of the glenoid neck on clinical outcome

A scapular neck fracture is considered unstable if it is associated with an ipsilateral clavicular fracture or an acromioclavicular (AC) joint dislocation. Currently, it is recommended that stabilization of a disrupted shoulder girdle must be achieved through open reduction and internal fixation of the clavicular fracture or by reduction of the AC joint, without addressing the scapular neck. However, if the displaced glenoid neck is not simultaneously reduced, malalignment of the glenoid neck may persist. The purpose of this retrospective study was to analyze the effect of associated shoulder girdle injury on glenoid displacement and the influence of glenoid malalignment on clinical outcome. Nineteen patients with scapular neck fractures were reviewed clinically and radiologically at a mean of 8 years (range 2-21 years) after injury. None of them has developed nonunion of the scapular neck, and only one showed radiological signs of mild degenerative joint disease. The glenopolar angle (GPA), which assesses the rotational malalignment of the glenoid about an anteroposterior axis perpendicular to the scapular plane on plain X-rays was measured less than 20 degrees in six patients. Three of them had sustained an associated clavicular fracture or AC joint dislocation. The other 3 patients had permanent severe malalignment of the glenoid neck in the absence of an associated shoulder girdle injury. Five patients with GPA less than 20 degrees complained of moderate or severe pain, whereas of the 13 patients with mild or no glenoid rotational displacement or medial displacement alone, 11 patients had no or mild pain, and only 2 had moderate or severe pain (P = 0.0095). Five patients presented with reduced activities of daily living, 4 of them had severe glenoid rotational displacement (P = 0.0173). Loss of motion was found in only 2 patients, and both had a severely displaced glenoid neck (P = 0.088). In conclusion, severe displacement of the glenoid neck may occur with or without associated fracture of the clavicle or dislocation of the AC joint and can be identified as a GPA less than 20 degrees. Scapular neck fractures with such malalignment have a less favorable long-term outcome compared with otherwise comparable cases with absence of glenoid malalignment as measured with the glenopolar angle.

Expression of an endothelial-type nitric oxide synthase isoform in human neutrophils: modification by tumor necrosis factor-alpha and during acute myocardial infarction

OBJECTIVES

The purpose of this study was to determine whether human neutrophils express an endothelial-type nitric oxide synthase (eNOS), and to study the effect of tumor necrosis factor-alpha (TNF-alpha) on its expression.

BACKGROUND

Several studies have demonstrated the presence of a constitutively expressed nitric oxide svnthase (NOS) in neutrophils. Cardiovascular disease is characterized by increased levels of plasma TNF-alpha, a cytokine that has demonstrated eNOS messenger ribonucleic acid (mRNA) destabilization in cultured endothelial cells.

METHODS

Neutrophils were obtained from healthy volunteers and from patients with acute myocardial infarction (AMI).

RESULTS

Human neutrophils express eNOS mRNA and eNOS protein. Stimulation of neutrophils with TNF-alpha decreased eNOS protein expression by reducing eNOS mRNA stabilization. In the present study, we also show that the cytosol of human neutrophils contains proteins that bind to a specific region within the 3'-untranslated region (3'-UTR) of eNOS mRNA. Tumor necrosis factor-alpha increased the binding of the cytosolic proteins to the 3'-UTR of eNOS mRNA. Simvastatin reduced the TNF-alpha-related binding activity of neutrophil cytosolic proteins to eNOS mRNA, which was associated with its protective effect on eNOS protein expression. The in vivo reproduction of the in vitro findings was performed in neutrophils obtained from patients with AMI and showed a diminished expression of eNOS protein, which was associated with increased binding of the cytosolic proteins.

CONCLUSIONS

These observations demonstrate that human neutrophils express eNOS, which is downregulated by TNF-alpha and during AMI. This effect is associated with increased binding of neutrophil cytosolic proteins to the 3'-UTR of eNOS mRNA.

Mutations in a conserved enteroviral RNA oligonucleotide sequence affect positive strand viral RNA synthesis

We showed earlier that a transition mutation U234C, located within the completely conserved 5 nucleotide (nt) tract 5'-CGUUA (nt232-236) in the 5' non-translated region (NTR) of the coxsackievirus B3 (CVB3) genome, attenuated CVB3 cardiovirulence in mice. To further explore the role of the sequence, we induced two single and one double transversion mutations in the conserved 5mer in a cardiovirulent CVB3 genome. The mutated sites partially or totally reverted to parental wild-type when progeny viruses were passaged at 37 degrees C, but remained stable when transfection and subsequent passages were performed at 33.5 degrees C. Viral replication in cell culture was attenuated at 37 degrees C or 39.5 degrees C relative to replication at 33.5 degrees C. While Western blot analysis demonstrated the level of protein translation consistent with virus replication, the ratios of positive to negative strand viral RNA at 37 degrees C in murine cells demonstrated a 2-5 fold diminution from those measured at 33.5 degrees C. Mutant CVB3 strains failed to replicate productively when inoculated into mice. The biological data are consistent with an hypothesis that proposes a lesion with primary effects at the level of positive strand viral RNA synthesis that results in attenuation of viral replication at physiologic temperature.

Colorimetric and spectroradiometric characteristics of narrow-field-of-view clear skylight in Granada, Spain

As part of our ongoing research into the clear daytime sky's visible structure, we analyze over 1,500 skylight spectra measured during a seven-month period in Granada, Spain. We use spectral radiances measured within 3 degrees fields of view (FOV's) to define colorimetric characteristics along four sky meridians: the solar meridian and three meridians at azimuths of 45 degrees, 90 degrees, and 315 degrees relative to it. The resulting clear-sky chromaticities in 44 different view directions (1) are close to but do not coincide with the CIE daylight locus, (2) form V-shaped meridional chromaticity curves along it (as expected from theory), and (3) have correlated color temperatures (CCT's) ranging from 3,800 K to infinity K. We also routinely observe that sky color and luminance are asymmetric about the solar meridian, usually perceptibly so. A principal-components analysis shows that three vectors are required for accurate clear-sky colorimetry, whereas six are needed for spectral analyses.

Analysis of discrimination threshold on the tritan axis

Discrimination thresholds on the tritan axis were obtained for an extensive group of 66 stimuli: in some of the stimuli, S-cone trolands were held constant by keeping the product of the S-cone excitation level and the luminance unchanged, while in others only the luminance was changed to establish various S-cone troland values. These thresholds depended clearly on the S-cone value of the stimuli, while they remained almost constant against the retinal illumination. Thus, we noted that the excitation of the L - 2M channel had practically no influence over the discrimination threshold on the tritan axis, although this independence of delta S from L - 2M was not so obvious when the S value was high. With our data, we performed different fits, and found that the fit including the terms S, (L - 2M) and (L + M) adapted better to our results.

Enteroviral meningitis. Cost of illness and considerations for the economic evaluation of potential therapies

With limited financial resources available, it is now becoming more acceptable to evaluate medical innovations in terms of incremental economic value. The purpose of this paper is to provide an overview of enteroviral meningitis and to summarise the economic literature to identify relevant costs and outcomes. Enteroviral meningitis is the most common cause of aseptic meningitis, and occurs in 4.5 to 30 per 100,000 population annually with a duration of illness lasting between 1 and 2 weeks after onset of initial symptoms. The major resource categories that contribute to the overall direct costs of management of enteroviral meningitis include physician visits, hospital admissions, emergency room visits, medications, procedures such as lumbar puncture and computed tomography scans, re-hospitalizations and follow-up physician visits. Indirect costs are incurred in terms of school or work days missed or restrictions in daily activities. The total direct costs of an episode of enteroviral meningitis range from $US450 for outpatients to $US5093 for inpatient management (1996 values). The total indirect costs of an episode of enteroviral meningitis are estimated to be equivalent to 5 to 7 activity-restricted days. Interventions that improve early diagnosis or decrease the duration and need for hospitalisation will significantly affect the cost of managing enteroviral meningitis. Additional prospective studies are needed to study the impact of interventions on the burden of enteroviral meningitis.

[Results of a psychotherapeutic program for smoking after 12 months of follow-up]

OBJECTIVE

To compare the efficacy of psychological counseling for smokers in a cessation program in comparison with treatment based only on providing information about damage caused by tobacco and advice for quitting, and to determine the reasons patients started to smoke.

PATIENTS AND METHODS

We studied 249 patients who came to a preliminary interview; 226 began treatment for smoking cessation. The average level of dependence, quantified the Fagerstrom test was 7.26 +/- 1.85 points. Two treatment groups were formed: the first patients seen made up the control group (n = 37), which received information about the dangers of tobacco and strategies for quitting, and the psychological counseling group (n = 189). Follow-up examinations were performed three, six and twelve months after treatment, with abstinence checked by measurement of CO in exhaled air. Only patients with CO levels less than 5 ppm (particles per million) in exhaled air were considered non-smokers.

RESULTS

Most patients of both sexes named social pressure as the reason for starting to smoke. The rate of abstinence in the information and strategies group was 8.1% at all three follow-up visits, whereas the rate was 37%, 25.4% and 24.3% at three, six and twelve months, respectively, in the group receiving counseling. The differences between the two groups were significant at all visits.

CONCLUSIONS

Social pressure is the main reason for starting to smoke. We observed a success rate of 24.3% after one year of follow-up after psychological treatment only, a rate that was significantly higher than that of the group that received only information. We believe that psychological counseling is an effective alternative for smokers who want to quit.

Intracytoplasmic sperm injection with cryopreserved testicular spermatozoa

To assess if testicular sperm cryopreservation is a valid alternative to repetition of testicular sperm retrieval techniques, results of a cryopreservation technique in pills have been retrospectively analyzed. Enough motile spermatozoa for ICSI were obtained in 172 from 190 (90.5%) frozen-thawed testicular sperm samples. Overall, 249 couples underwent 390 ICSI cycles, 156 using fresh and 234 using cryopreserved testicular sperm. Mean two-pronuclear fertilization rates per cycle were not significantly different after ICSI with fresh (62.0%) or with cryopreserved (63.2%) spermatozoa. Mean embryo cleavage rate per cycle was higher in the fresh (90.6%) than in the cryopreserved (84.6%) group (P = 0.016). However, clinical pregnancy rates per cycle (28.2% with fresh vs 27.8% with cryopreserved), implantation rates (12.2% vs 13.1%) and ongoing pregnancy rates per cycle (22.4% vs 21.8%) were not significantly different. Cryopreservation of testicular spermatozoa is an effective technique that can be used both in obstructive and in non-obstructive azoospermia.

Therapeutic decision tree for patients with sustained ventricular tachyarrhythmias or aborted cardiac arrest: a critical review of the Antiarrhythmics Versus Implantable Defibrillator trial and the Canadian Implantable Defibrillator Study

Antiarrhythmic drugs, mainly amiodarone and sotalol, radiofrequency catheter ablation, and the implantable cardioverter defibrillator (ICD) are the 3 therapeutic options in patients with sustained ventricular tachycardia (VT) or ventricular fibrillation (VF). Idiopathic VT, incessant VT, frequently recurring, hemodynamically stable VT, and VT based on bundle branch reentry, are candidates for radiofrequency catheter ablation. Patients with high-risk ventricular tachyarrhythmias should receive ICDs as initial therapy. Two studies, the Antiarrhythmics Versus Implantable Defibrillator trial (AVID) and the Canadian Implantable Defibrillator Study (CIDS) have tried to approach the problem of these high-risk ventricular tachyarrhythmias. Although at 3 years, the ICD in AVID demonstrated a significant relative risk reduction over amiodarone of 31.5%, CIDS could not duplicate this finding. At 3 years, the relative risk reduction conferred by the ICD over amiodarone in CIDS was only 13.7%. A careful analysis of both studies suggests that CIDS was insufficiently powered to demonstrate statistically significant benefits similar to those shown by AVID, and furthermore, seemed to include an undetermined number of low-risk VT patients. The problem in the CIDS trial in this regard was the recruitment of patients in whom the inclusion criteria were met by the arrhythmias induced during the electrophysiology stimulation study, but which did not exist in real life. In addition CIDS included 14% of patients with (1) undocumented syncope and inducible monomorphic sustained VT; or (2) long runs of spontaneous nonsustained VT. Under these circumstances, the therapeutic implications of AVID remain unchallenged.

Femoral trochlear dysplasia: MR findings

PURPOSE

To establish quantitative and qualitative magnetic resonance (MR) criteria for the diagnosis of trochlear dysplasia.

MATERIALS AND METHODS

MR images were analyzed in 16 consecutive patients with and 23 without trochlear dysplasia. The standard of reference was a true lateral radiograph of the knee. Quantitative and qualitative MR criteria were assessed.

RESULTS

In patients with trochlear dysplasia, the trochlear groove was significantly less deep than that in control subjects. The most accurate measurement was 3 cm above the femorotibial joint space (P: <.001), where a trochlear depth of 3 mm or less had a sensitivity of 100% and a specificity of 96%. The ventral trochlear prominence between the supratrochlear femoral cortex and the most ventral point of the trochlear floor (midsagittal section) was always larger than 6.9 mm in dysplastic trochleae. A facet ratio of less than 2:5 (medial to lateral) 3 cm above joint space level had a sensitivity of 100% and a specificity of 96%. A nipplelike anterior prominence at the superior end of the femoral trochlea on midsagittal images was a specific (91%) qualitative criterion.

CONCLUSION

Dysplasia of the femoral trochlea can be diagnosed reliably by using quantitative or qualitative criteria on midsagittal or transverse MR images obtained 3 cm above the femorotibial joint space.

Stochastic independence of color-vision mechanisms confirmed by a subthreshold summation paradigm

We have used a subthreshold summation protocol to analyze spatial color-color interaction. By means of a CRT color monitor, we measured the threshold contours for a spatial frequency of 0.5 cycles/degree. Heterochromatic flicker photometry was used to obtain isoluminance. The results suggest that the blue-yellow (b-y) and red-green (r-g) contrast thresholds remained unchanged by the addition of fixed r-g and b-y subthreshold pedestals. Our subthreshold summation data then support the stochastic independence of colorvision mechanisms derived from Mullen and Sankeralli's work [Vision Res. 39, 733 (1999)] despite the differences that exist between the two experimental methods.

Spontaneous osteonecrosis of the medial compartment of the knee: a MRI follow-up after conservative and operative treatment, preliminary results

Symptoms in patients suffering from spontaneous osteonecrosis of the knee (SONK) may be reduced by high tibial osteotomy (HTO). However, the fate of the necrotic lesion is unknown and needs further investigation. We conducted a prospective study to evaluate magnetic resonance imaging (MRI) changes after operative and nonoperative treatment. Ten consecutive patients suffering from SONK of the medial compartment were given two treatment options: either HTO (n = 6) or conservative treatment with partial weight bearing for 3 months (n = 4). We measured the greatest extent of well-defined subchondral low signal intensity abnormality, considered to represent necrosis, and the surrounding area of intermediate signal intensity, considered to represent perifocal bone marrow edema, on T1-weighted coronal MRI images before and after treatment. The MRI follow-up period was 17.5 months (range 12-27) in the HTO group and 14.5 months (range 8-25) in the nonoperative group. At follow-up the MRI evaluation revealed a decrease in the low signal intense areas (necrosis) in five of the six patients in the HTO group. Only one of the four nonoperative patients showed a decrease in the low signal intense area. The intermediate intense areas (edema) decreased in all patients in the HTO group and in three of four in the nonoperative group. The mean decrease in the area of perifocal edema was significantly greater in the HTO group than in the nonoperative group (P = 0.019). No statistically significant difference was found for the area of necrosis between the two groups (P = 0.171). A clinical improvement was observed in all patients of the HTO group but in only two of the four patients of the nonoperative group. We conclude that the decrease in perifocal bone marrow edema seems to be associated with improved patient comfort. The MRI appearance of the necrotic lesion does not alter with either treatment mode.

Visual system's adjustments to illuminant changes: heuristic-based model revisited

This study evaluates the effect of illuminant changes along the two post-receptoral mechanisms: red-green (L - 2M) and yellow-blue (L + M - S). By means of a CRT colour monitor, Mondrian-type scenes were simulated and a series of asymmetric colour matches were made with five test illuminants. The standard objects comprising the scenes were simulations of surfaces under equal-energy illuminant and were selected according to lines of equal excitation of the red-green and the yellow-blue mechanisms. Results show that observers' matches are well predicted by assuming affine transformations between test and standard illuminant conditions. The best linear fits derived from the data corroborates the previous heuristic-based algorithms [Zaidi Q. (1998) Journal of the Optical Society of America A. 7. 1767-1776] although some discrepancies were found. Results along red-green mechanism confirm that the significant effect of the illuminant is an additive change along this axis, while data for yellow-blue mechanism suggest that illuminant induces not only multiplicative changes along this axis but additive too. In addition, we found that memory factors involved in the experiment could influence the observers' matches and would be taken into account as responsible of the differences found between the yellow-blue and the red-green systems.

First Detection of Faba bean necrotic yellow virus in Spain

Faba bean necrotic yellow virus (FBNYV) was not detected during 1994 to 1996 field surveys of faba beans (Vicia faba L.) in Spain (1). In 1997, however, one sample with symptoms of necrosis, collected in Baleares, was tested using ELISA (enzyme-linked immunosorbent assay) and was positive for both Tomato spotted wilt virus (TSWV) and FBNYV. FBNYV is a single-strand DNA virus that is transmitted by aphids and is the main virus disease of broad bean in North Africa and West Asia (2). During 1997 to 1999, faba bean plants with symptoms of necrosis, yellowing, small leaves, and stunting were collected from several fields in the Murcia Region (Spain) and were analyzed using ELISA. To detect FBNYV, we used monoclonal 2E9 supplied by H. J. Vetten (Institute of Plant Virology, Microbiology and Biosafety, BBA, Braunschweig, Germany). Of 700 samples analyzed, 34 were positive for FBNYV. Of the 34 positive samples, 12 tested positive, using commercial antiserum from Loewe, Inc. (Munich) for mixed infections with TSWV. FBNYV was transmitted to healthy faba bean plants by aphids (Acyrthosiphon pisum) in greenhouse experiments and was confirmed by ELISA. Preliminary epidemiological data showed a gradual increase in the number of plants infected with time in the same field. Aphid transmission of FBNYV to faba beans has established the disease in Spain and is a potential threat to other leguminous crops. This is the first report of a nanovirus in Europe. References: (1) J. Fresno et al. Plant Dis. 81:112, 1997. (2) L. Katul et al. Ann. Appl. Biol. 123:629, 1993.

Bone marrow edema pattern in osteoarthritic knees: correlation between MR imaging and histologic findings

PURPOSE

To correlate magnetic resonance (MR) images of a bone marrow edema pattern with histologic findings in osteoarthritic knees.

MATERIALS AND METHODS

Sixteen consecutive patients (age range, 43-79 years; mean, 67 years) referred for total knee replacement were examined with sagittal short inversion time inversion-recovery (STIR) and T1- and T2-weighted turbo spin-echo MR imaging 1-4 days before surgery. Tibial plateau abnormalities on MR images were compared quantitatively with those on histologic maps.

RESULTS

The bone marrow edema pattern zone (ill-defined and hyperintense on STIR images and hypointense on T1-weighted MR images) mainly consisted of normal tissue (53% of the area was fatty marrow, 16% was intact trabeculae, and 2% was blood vessels) and a smaller proportion of several abnormalities (bone marrow necrosis [11% of area], abnormal [necrotic or remodeled] trabeculae [8%], bone marrow fibrosis [4%], bone marrow edema [4%], and bone marrow bleeding [2%]). The bone marrow edema pattern zone and the zone with a normal MR imaging appearance differed significantly in the presence of bone marrow necrosis (P =.021), bone marrow fibrosis (P =.014), and abnormal trabeculae (P =.011) but not in the prevalence of bone marrow edema (P =.069). Bone marrow edema also was found in zones with an unremarkable MR appearance (perifocal zone, 5% edema; control zone, 2% edema).

CONCLUSION

A bone marrow edema pattern in osteoarthritic knees represents a number of noncharacteristic histologic abnormalities. Edema is not a major constituent of MR imaging signal intensity abnormalities in such knees.