[Toxicity of radiation therapy and antiangiogenics combination: a case report]

The combined administration of antiangiogenic agents (AA) and radiation is being evaluated. No AA has yet received Marketing Authorization in this indication. However, they are widely used in medical oncology and criteria for stopping their administration in case of irradiation have not been defined. We report the case of a 63-year-old man experiencing grade 2 skin toxicity while on radiation treatment and sorafenib (400mg twice daily) for a metastatic lesion developing between the vastus medialis muscle and the cortical of the mid-diaphysis of the right femur. Toxicity occurred at 21Gy, for a total dose of 36Gy (12 fractions of 3Gy). Cutaneous symptoms rapidly disappeared after treatment discontinuation. Radiotherapy alone was resumed after a few days and the total dose could be delivered, with good tolerance. At 2-month follow-up, the intramuscular lesion had regressed. Several other cases of patients with poor tolerance to the association of AA and radiotherapy have been reported. Further studies of the effectiveness and tolerance of the combination treatment are needed before indications for AA can be extended to other diseases.

Effects of larval exposure to sublethal concentrations of methoxyfenozide in Spodoptera frugiperda (J.E. Smith)

Methoxyfenozide is an ecdysone agonist, the most new class of insect growth regulators. Most studies of the toxicity of ecdysone agonists on lepidopteran pests have been conducted during the larval stages, and little has been published regarding its sublethal effects in the surviving individuals. In this study, the lethal and sublethal effects of methoxyfenozide on the fall armyworm, Spodoptera frugiperda (J. E. Smith) (Lepidoptera: Noctuidae) were assessed. For this, fifth instars of this pest were continuously fed, until pupation, with artificial diet containing 0.24 and 0.35 mg of active ingredient/kg diet, which correspond to the LC10 and LC25 values, respectively, for this insecticide. Larval mortality reached 8% and 26% in the low and high concentration groups, respectively, on the seventh day of the experiment. A progressive larval mortality of 12% for the LC10 and 60% for the LC25 was observed before pupation. Treated larvae exhibited lower pupal weights, higher pupal mortality, presence of deformed pupae, and more deformed adults than untreated larvae. The incorporation of methoxyfenozide into the diet had a significant effect on the timing of larval development. Both male and female treated larvae lived about seven days longer than the controls for both concentrations tested. Finally, S. frugiperda adults that resulted from fifth instars treated with methoxyfenozide were not affected in their sex ratio. Our results suggest that the combination of lethal and sublethal effects of methoxyfenozide may have important implications for the population dynamics of the fall armyworm.

Assessment of total mercury levels in Clarias gariepinus from the Sagua la Grande River, Cuba

Total mercury levels (Thg) were quantified in Clarias gariepinus captured from the Sagua la Grande River (Cuba) in the vicinity of an active chlor-alkali plant, and relationships among place of capture; fish size, weight, and sex; and THg levels were assessed. THg levels ranged from 67 to 375 ng/g ww in collected fish, never exceeding the Cuban recommended maximum limit for fish consumption of 500 ng/g ww. No significant correlation was observed between mercury levels and fish allometric characteristics (p < 0.05); however, levels were significantly higher in fish captured below the chlor-alkali facility, suggesting a connection between mercury bioaccumulation and plant discharges.

Intimal Thickening after Placement of a Neuroform Stent. Its Incidence and Relation to Angiographic Follow-up Results of Aneurysm Embolization

SUMMARY

Little attention has been given to the intimal thickening of the parent artery associated with the use of Neuroform stent. The purposes of this study were are to analyze quantifyanalyze the incidence of the parent artery intimal thickening the incidence and pattern of luminal changes, to to see somedetermine possible predictors of the phenomenonof the intimal thickening, to to evaluate the its effectthe phenomenonrestenosis on the aneurysm treatment results. We reviewed the initial and six-month followup angiographic images in 32 intracranial aneurysm patients treated with Neuroform stent and coilsin wide-necked aneurysm treatment. The initial embolization results were evaluated by the Raymond and Roy classification. The angiographic changes from immediate post-embolization to the six-month follow-up were classified as 'improved', 'unchanged' and 'worse'. The occurrencerates of parent artery intimal thickening was observed. Any perceivable change in the stented segment of the parent artery was considered as 'intimal thickening' and any change of >/=50% as 'significant thickening'. Fisher exact tests and logistic regression analysis were applied to determine the relation between the occurrence of the intimal thickening and several variables. The incidence of the intimal thickening was 18.8% (6/32) and of significant thickening, 3.1% (1/32). The change in angiographic occlusion of the aneurysm was 'improved' in 40.6% (13/32), 'unchanged' in 37.5% (12/32), and 'worse' in 21.9% (7/32). Among the variables, patient's age (>/=55) and follow-up angiographic results ('improved') correlated with the occurrence of the intimal thickening. Of notable finding was all six cases with intimal thickening of the parent artery were associated with 'improved' in their followup angiographic result. Neuroform-associated intimal thickening usually occurs in younger patients and is frequently associated with improved angiographic result of the aneurysm embolization on follow-up.

Microglandular adenosis of the breast in a BRCA1 mutation carrier: radiological features

Microglandular adenosis is a very uncommon benign proliferative disorder of the breast that may mimic tubular carcinoma radiologically and pathologically. We describe the radiological features of this rare condition in a patient with BRCA 1 mutation. To our knowledge, this is the first case of microglandular adenosis reported in the radiology literature. The relationship between microglandular adenosis and malignancy and the association between BRCA 1 and proliferative benign disorders are also discussed.

Role of inspiratory capacity on exercise tolerance in COPD patients with and without tidal expiratory flow limitation at rest

Expiratory flow limitation promotes dynamic hyperinflation during exercise in chronic obstructive pulmonary disease (COPD) patients with a consequent reduction in inspiratory capacity (IC), limiting their exercise tolerance. Therefore, the exercise capacity of patients with tidal expiratory flow limitation (FL) at rest should depend on the magnitude of IC. The presented study was designed to evaluate the role of FL on the relationship between resting IC, other respiratory function variables and exercise performance in COPD patients. Fifty-two patients were included in the study. Negative expiratory pressure (NEP) uptake (VO2,max) were measured during an incremental symptom-limited cycle exercise. Twenty-nine patients were FL at rest. The IC was normal in all non-FL patients, while in most FL subjects it was decreased. Both WRmax and VO2,max were lower in FL patients (p<0.001, each). A close relationship of WRmax and O2,max to IC was found (r=0.73 and 0.75, respectively; p<0.0001, each). In the whole group, stepwise regression analysis selected IC and forced expiratory volume in one second (FEV1)/forced vital capacity (FVC) (% predicted) as the only significant contributors to exercise tolerance. Subgroup analysis showed that IC was the sole predictor in FL patients, and FEV1/FVC in non-FL patients. Detection of flow limitation provides useful information on the factors that influence exercise capacity in chronic obstructive pulmonary disease patients. Accordingly, in patients with flow limitation, inspiratory capacity appears as the best predictor of exercise tolerance, reflecting the presence of dynamic hyperinflation.

Effects of F(I)O2 on leg VO2 during cycle ergometry in sedentary subjects

In a recent study of completely sedentary normal young subjects, leg VO2max was reduced by hypoxia in proportion to mean capillary PO2 as F(I)O2 was reduced from 0.15 to 0.12. However, the increase in VO2max from F(I)O2 = 0.15 to 0.21 was less than expected for the increase in mean capillary PO2. This finding has led us to hypothesize that in sedentary subjects breathing room air, VO2max is not limited by O2 supply but rather by oxidative capacity of mitochondria. The present study sought to obtain further evidence for or against this hypothesis in sedentary subjects by assessing leg VO2max (VO2leg) breathing 100% O2, as well as in normoxia and hypoxia. Data from 18 subjects studied at F(I)O2 = 0.12, 0.15, and 0.21 and from six more studied at 0.12, 0.15, and 1.00 were analyzed. In all 24 we measured VO2leg by arterial and venous blood sampling and thermodilution leg blood flow during maximal cycle ergometry at each F(I)O2. VO2leg was not increased by room air or 100% O2 breathing relative to that observed at F(I)O2 = 0.15, but it was reduced while breathing 12% O2. The data at F(I)O2 = 0.12 and 0.15 conformed to the predictions of O2 supply limitation of maximal VO2 as previously. These results confirm and extend our prior observations that in sedentary, as opposed to trained subjects, muscle VO2max is O2 supply limited only in hypoxia.

Effects of noninvasive ventilation on pulmonary gas exchange and hemodynamics during acute hypercapnic exacerbations of chronic obstructive pulmonary disease

Noninvasive positive pressure ventilation (NIPPV) can replace tracheal intubation in acute exacerbations of chronic obstructive pulmonary disease (COPD) with severe hypercapnic respiratory failure. However, the underlying mechanisms by which NIPPV improves pulmonary gas exchange are not known. We studied 10 male COPD patients (68 +/- 8 [SD] yr) with acute severe hypercapnic respiratory failure within 36 h after hospital admission. Measurements of pulmonary gas exchange, hemodynamics, and respiratory mechanics were done: (I) breathing spontaneously (baseline); (2) after 15 and 30 min of NIPPV with pressure support (inspiratory pressure = 12 +/- 2 cm H20, PEEP = 3 +/- 2 cm H20); and (3) 15 min after NIPPV withdrawal. Patients were ventilated using a full face mask, keeping FIO2 constant (0.23 +/- 0.02) in all conditions. Compared with baseline, during NIPPV (15 min) we observed a moderate increase in Pa02 (from 50 +/- 6 to 57 +/- 9 mm Hg; p < 0.05), and a fall in PaCO2 (from 66 +/- 10 to 59 +/- 10 mm Hg; p < 0.0001), but AaPO2 increased (from 39 +/- 13 to 48 +/- 13 mm Hg; p < 0.001). Breathing frequency decreased (from 26 +/- 5 to 19 +/- 3 breaths/min; p < 0.0001), tidal volume increased (from 311 +/- 42 to 520 +/- 133 ml; p < 0.0001), and minute ventilation increased (from 8.0 to 1.7 to 9.6 +/- 2.0 L/min; p < 0.05). Cardiac output fell during NIPPV in all patients (from 6.7 +/- 1.6 to 5.8 +/- 1.3 L/min; p < 0.0025) with no impact on mixed venous PO2. No substantial changes in VA/Q mismatching (multiple inert gas elimination technique) were observed. While oxygen uptake showed a trend to decrease, the respiratory exchange ratio (R) increased (from 0.78 +/- 0.17 to 0.90 +/- 0.22; p < 0.001). The effects of NIPPV were unchanged at 30 min compared with 15 min and were reversed after 15 min of NIPPV withdrawal. We conclude that improvement in respiratory blood gases during NIPPV is essentially due to higher alveolar ventilation (p < 0.001) and not to improvement in VA/Q relationships. The increase in AaPO2 was explained by the rise in R due to an increased clearance of body stores of C02 during NIPPV. Our results indicate that attainment of an efficient breathing pattern rather than high inspiratory pressures should be the primary goal to improve arterial blood gases during NlPPV in this type of patient.

Increase in pulmonary ventilation-perfusion inequality with age in healthy individuals

Arterial oxygen tension (PaO2) is known to decrease with age, and this is accompanied by a number of changes in mechanical properties of the lungs, including loss of elastic recoil and increase in closing volume. The changes in respiratory mechanics with age could induce greater ventilation/perfusion (VA/Q) mismatch and thus explain the decrease in PaO2. In 64 normal subjects aged 18 to 71 yr (lifetime nonsmokers with normal spirometry), we measured VA/Q inequality and arterial respiratory blood gases (PaO2 and PaCO2) at rest in the seated position. VA/Q mismatch, represented by the second moments of the blood flow and ventilation distributions (log SDQ and log SDV) increased with age, but only slightly (mean log SDQ was 0.36 at age 20 yr and 0.47 at age 70 yr). PaO2 fell by a correspondingly small amount of 6 mm Hg. Previously established upper 95% confidence limits for log SDQ (0.60) and log SDV (0.65) in subjects at age 20 yr were confirmed. At age 70 yr, the upper limits of reference for log SDQ are 0.70 and for log SDV 0.75. The study shows that an increased alveolar-arterial O2 gradient with age is due to VA/Q inequality rather than to shunting.

Adjustment of DLCO for hemoglobin concentration

The equation proposed by Cotes and coworkers is currently considered as the most acceptable to correct carbon monoxide diffusing capacity (DLCO) for hemoglobin concentration [Hb] by both the American Thoracic Society (ATS) and the European Respiratory Society (ERS) guidelines for standardization of DLCO. In a previous study on 24 anemic patients undergoing bone marrow transplantation (1), we found that DLCO is underestimated using the equation of Cotes and coworkers. To further explore this finding, 28 anemic patients ([Hb] = 8.2 +/- 1.0 (SD) g/dl) with chronic renal failure were prospectively studied during the recovery period of anemia (5.4 +/- 3.5 mo). In all 28 subjects, the slope deltaDLCO/delta[Hb] computed as ratio of overall change in DLCO to overall change in [Hb] throughout the study period was 1.40 +/- 0.72 ml CO/min/mm Hg/g/dl. The individual relationship between measured DLCO and [Hb] closely fitted a simple linear regression. The resulting equations for adjustment of DLCO (DLCOadj) to a standard [Hb] of 14.6 g/dl for men and 13.4 g/dl for women are: [equations: see text]. The present adjustment function for DLCO is linear and independent of the observed DLCO values, whereas the formulas previously proposed are curvilinear, DLCO correction varying with the measured DLCO values. For a measured DLCO of 15 ml CO/min/mm Hg and [Hb] ranging from 7 to 12 g/dl, the present DLCO adjustment is higher (by 2.7 ml CO/min/mm Hg, on average) than that proposed by Cotes and coworkers. This difference appears to be relevant for a precise interpretation of DLCO in patients with normocytic anemia in different clinical conditions.

Cellular bioenergetics after erythropoietin therapy in chronic renal failure

After erythropoietin (rHuEPO) therapy, patients with chronic renal failure (CRF) do not improve peak O2 uptake (VO2 peak) as much as expected from the rise in hemoglobin concentration ([Hb]). In a companion study, we explain this phenomenon by the concurrent effects of fall in muscle blood flow after rHuEPO and abnormal capillary O2 conductance observed in CRF patients. The latter is likely associated with a poor muscle microcirculatory network and capillary-myofiber dissociation due to uremic myopathy. Herein, cellular bioenergetics and its relationships with muscle O2 transport, before and after rHuEPO therapy, were examined in eight CRF patients (27 +/- 7.3 [SD] yr) studied pre- and post-rHuEPO ([Hb] = 7.8 +/- 0.7 vs. 11.7 +/- 0.7 g x dl-1) during an incremental cycling exercise protocol. Eight healthy sedentary subjects (26 +/- 3.1 yr) served as controls. We hypothesize that uremic myopathy provokes a cytosolic dysfunction but mitochondrial oxidative capacity is not abnormal. 31P-nuclear magnetic resonance spectra (31P-MRS) from the vastus medialis were obtained throughout the exercise protocol consisting of periods of 2 min exercise (at 1.67 Hz) at increasing work-loads interspersed by resting periods of 2.5 min. On a different day, after an identical exercise protocol, arterial and femoral venous blood gas data were obtained together with simultaneous measurements of femoral venous blood flow (Qleg) to calculate O2 delivery (QO2leg) and O2 uptake (VO2leg). Baseline resting [phosphocreatine] to [inorganic phosphate] ratio ([PCr]/[Pi]) did not change after rHuEPO (8.9 +/- 1.2 vs. 8.8 +/- 1.2, respectively), but it was significantly lower than in controls (10.9 +/- 1.5) (P = 0.01 each). At a given submaximal or peak VO2leg, no effects of rHuEPO were seen on cellular bioenergetics ([PCr]/[Pi] ratio, %[PCr] consumption halftime of [PCr] recovery after exercise), nor in intracellular pH (pHi). The post-rHuEPO bioenergetic status and pHi, at a given VO2leg, were below those observed in the control group. However, at a given pHi, no differences in 31P-MRS data were detected between post-rHuEPO and controls. After rHuEPO, at peak VO2, Qleg fell 20% (P < 0.04), limiting the change in QO2leg to 17%, a value that did not reach statistical significance. The corresponding O2 extraction ratio decreased from 73 +/- 4% to 68 +/- 8.2% (P < 0.03). These changes indicate that maximal O2 flow from microcirculation to mitochondria did not increase despite the 50% increase in [Hb] and explain how peak VO2leg and cellular bioenergetics (31P-MRS) did not change after rHuEPO. Differences in pHi, possibly due to lactate differences, between post-rHeEPO and controls appear to be a key factor in the abnormal muscle cell bioenergetics during exercise observed in CRF patients.

Effects of erythropoietin on muscle O2 transport during exercise in patients with chronic renal failure

Erythropoietin (rHuEPO) has proven to be effective in the treatment of anemia of chronic renal failure (CRF). Despite improving the quality of life, peak oxygen uptake after rHuEPO therapy is not improved as much as the increase in hemoglobin concentration ([Hb)] would predict. We hypothesized that this discrepancy is due to failure of O2 transport rates to rise in a manner proportional to [Hb]. To test this, eight patients with CRF undergoing regular hemodialysis were studied pre- and post-rHuEPO ([Hb] = 7.5 +/- 1.0 vs. 12.5 +/- 1.0 g x dl-1) using a standard incremental cycle exercise protocol. A group of 12 healthy sedentary subjects of similar age and anthropometric characteristics served as controls. Arterial and femoral venous blood gas data were obtained and coupled with simultaneous measurements of femoral venous blood flow (Qleg) by thermodilution to obtain O2 delivery and oxygen uptake (VO2). Despite a 68% increase in [Hb], peak VO2 increased by only 33%. This could be explained largely by reduced peak leg blood flow, limiting the gain in O2 delivery to 37%. At peak VO2, after rHuEPO, O2 supply limitation of maximal VO2 was found to occur, permitting the calculation of a value for muscle O2 conductance from capillary to mitochondria (DO2). While DO2 was slightly improved after rHuEPO, it was only 67% of that of sedentary control subjects. This kept maximal oxygen extraction at only 70%. Two important conclusions can be reached from this study. First, the increase in [Hb] produced by rHuEPO is accompanied by a significant reduction in peak blood flow to exercising muscle, which limits the gain in oxygen transport. Second, even after restoration of [Hb], O2 conductance from the muscle capillary to the mitochondria remains considerably below normal.

Variance of the position of the cerebellar tonsils with age: preliminary report

The position of the cerebellar tonsils relative to the foramen magnum was measured with sagittal magnetic resonance (MR) images in 221 patients aged 5 months to 89 years who were considered not to have disorders that would affect tonsillar position. All patients were grouped according to age. All measurements of the tonsils were obtained directly from the video console. Statistically significant (P less than .05) differences in tonsillar position were found between the 1st and 9th decades (P less than .001) and the 3rd and 9th decades (P less than .003) of life. An obvious trend existed: tonsillar ascent with increasing age. Therefore, the authors believe that a single reference standard that indicates the normal distance of the cerebellar tonsils from the foramen magnum is inappropriate unless age is considered. They suggest that the following distances below the foramen magnum (more than 2 standard deviations out of the normal range) be used as criteria for ectopia of the cerebellar tonsils: 1st decade of life, 6 mm; 2nd and 3rd decades, 5 mm; 4th to 8th decades, 4 mm; and 9th decade, 3 mm.

Development of a hand sensitivity test for the hypersensitive hand

An instrument was developed to measure the effects of a desensitization program on hand hypersensitivity. It was standardized with 40 "normal" subjects ages 20 to 40 of both sexes and two ethnic groups. Results showed reliability coefficients ranging from .74 to .82 for the three modalities employed in the test. Analyses of variance of agreement between test and retest scores revealed no significant differences in reliability due to hand used, sex, or ethnicity. It was concluded that the instrument could be used as both a clinical and research tool for the measurement of hand sensitivity.