Evaluating TROPOMI and MODIS performance to capture the dynamic of air pollution in São Paulo state: A case study during the COVID-19 outbreak.

Atmospheric pollutant data retrieved through satellite sensors are continually used to assess changes in air quality in the lower atmosphere. During the COVID-19 pandemic, several studies started to use satellite measurements to evaluate changes in air quality in many different regions worldwide. However, although satellite data is continuously validated, it is known that its accuracy may vary between monitored areas, requiring regionalized quality assessments. Thus, this study aimed to evaluate whether satellites could measure changes in the air quality of the state of São Paulo, Brazil, during the COVID-19 outbreak; and to verify the relationship between satellite-based data [Tropospheric NO2 column density and Aerosol Optical Depth (AOD)] and ground-based concentrations [NO2 and particulate material (PM; coarse: PM10 and fine: PM2.5)]. For this purpose, tropospheric NO2 obtained from the TROPOMI sensor and AOD retrieved from MODIS sensor data by using the Multi-Angle Implementation of Atmospheric Correction (MAIAC) algorithm were compared with concentrations obtained from 50 automatic ground monitoring stations. The results showed low correlations between PM and AOD. For PM10, most stations showed correlations lower than 0.2, which were not significant. The results for PM2.5 were similar, but some stations showed good correlations for specific periods (before or during the COVID-19 outbreak). Satellite-based Tropospheric NO2 proved to be a good predictor for NO2 concentrations at ground level. Considering all stations with NO2 measurements, correlations >0.6 were observed, reaching 0.8 for specific stations and periods. In general, it was observed that regions with a more industrialized profile had the best correlations, in contrast with rural areas. In addition, it was observed about 57% reductions in tropospheric NO2 throughout the state of São Paulo during the COVID-19 outbreak. Variations in air pollutants were linked to the region economic vocation, since there were reductions in industrialized areas (at least 50% of the industrialized areas showed >20% decrease in NO2) and increases in areas with farming and livestock characteristics (about 70% of those areas showed increase in NO2). Our results demonstrate that Tropospheric NO2 column densities can serve as good predictors of NO2 concentrations at ground level. For MAIAC-AOD, a weak relationship was observed, requiring the evaluation of other possible predictors to describe the relationship with PM. Thus, it is concluded that regionalized assessment of satellite data accuracy is essential for assertive estimates on a regional/local level. Good quality information retrieved at specific polluted areas does not assure a worldwide use of remote sensor data.

How mobility restrictions policy and atmospheric conditions impacted air quality in the State of São Paulo during the COVID-19 outbreak.

Mobility restrictions are among actions to prevent the spread of the COVID-19 pandemic and have been pointed as reasons for improving air quality, especially in large cities. However, it is crucial to assess the impact of atmospheric conditions on air quality and air pollutant dispersion in the face of the potential variability of all sources. In this study, the impact of mobility restrictions on the air quality was analyzed for the most populous Brazilian State, São Paulo, severely impacted by COVID-19. Ground-based air quality data (PM10, PM2.5, CO, SO2, NOx, NO2, NO, and O3) were used from 50 automatic air quality monitoring stations to evaluate the changes in concentrations before (January 01 - March 25) and during the partial quarantine (March 16 - June 30). Rainfall, fires, and daily cell phone mobility data were also used as supplementary information to the analyses. The Mann-Whitney U test was used to assess the heterogeneity of the air quality data during and before mobility restrictions. In general, the results demonstrated no substantial improvements in air quality for most of the pollutants when comparing before and during restrictions periods. Besides, when the analyzed period of 2020 is compared with the year 2019, there is no significant air quality improvement in the São Paulo State. However, special attention should be given to the Metropolitan Area of São Paulo (MASP), due to the vast population residing in this area and exposed to air pollution. The region reached an average decrease of 29% in CO, 28% in NOx, 40% in NO, 19% in SO2, 15% in PM2.5, and 8% in PM10 concentrations during the mobility restrictions period compared to the same period in 2019. The only pollutant that showed an increase in concentration was ozone, with a 20% increase compared to 2019 during the mobility restrictions period. Before the mobility restrictions period, the region reached an average decrease of 30% in CO, 39% in NOx, 63% in NO, 12% in SO2, 23% in PM2.5, 18% in PM10, and 16% in O3 concentrations when compared to the same period in 2019. On the other hand, Cubatão, a highly industrialized area, showed statistically significant increases above 20% for most monitored pollutants in both periods of 2020 compared to 2019. This study reinforces that the main driving force of pollutant concentration variability is the dynamics of the atmosphere at its various time scales. An abnormal rainy season, with above average rainfall before the restrictions and below average after it, generated a scenario in which the probable significant reductions in emissions did not substantially affect the concentration of pollutants.

Predictive value of performance validity testing and symptom validity testing in psychoeducational assessment.

Using archival data from 2463 psychoeducational assessments of postsecondary students we investigated whether failure on either symptom or performance validity tests (SVTs or PVTs) was associated with score differences on various cognitive, achievement, or executive functioning performance measures or on symptom report measures related to mental health or attention complaints. In total, 14.6% of students failed one or more PVT, 33.6% failed one or more SVT, and 41.6% failed at least one validity test. Individuals who failed SVTs tended to have the highest levels of self-reported symptoms relative to other groups but did not score worse on performance-based psychological tests. Those who failed PVTs scored worse on performance-based tests relative to other groups. Failure on at least one PVT and one SVT resulted in both performance and self-reported symptoms suggestive of greater impairment compared with those who passed all validity measures. Findings also highlight the need for domain-specific SVTs; failing ADHD SVTs was associated only with extreme reports of ADHD and executive functioning symptoms while failing mental health SVTs related only to extreme reports of mental health complaints. Results support using at least one PVT and one SVT in psychoeducational assessments to aid in diagnostic certainty, given the frequency of non-credible presentation in this population of postsecondary students.

The impact of depression and anxiety on speed of academic performance and retrieval fluency in postsecondary students.

Objective: This study evaluated the functional effects of severe mental health symptoms on speed of academic performance to assist clinicians and educators in determining whether extra time accommodations are evidence-based for students with such diagnoses. Method: Using archival data from 1476 post-secondary students, we examined the performance of students with existing mental health diagnoses who were also reporting extremely high levels of symptoms. Their performance on timed academic achievement and cognitive processing measures was compared with performance of students with learning disabilities, Attention Deficit Hyperactivity Disorder, and clinical controls. Students failing stand-alone performance validity and/or symptom validity measures were excluded from this investigation. Results: Students diagnosed with anxiety and/or depression did not differ from clinical controls on any timed performance measure, typically performing academic tasks within a normal amount of time. By contrast, those with reading disabilities were typically the slowest on all academic tasks. Conclusion: Across the range of timed tests, students with mental health diagnoses did not show functional impairments in tests with a speed component. As such, they would not typically require increased time to perform speeded academic tasks, but they might require alternative accommodations in their post-secondary programmes in order to participate equally.

The effect of acetazolamide, amiloride, bumetanide and SITS on secretion of fluid and electrolytes by the parotid gland of common wombats, Vombatus ursinus.

Mechanisms of saliva formation by wombat parotid glands were investigated in anaesthetized wombats at two levels of cholinergically-stimulated flow viz. mid-range (30-40% maximum flow) and maximum flow using ion-transport and carbonic-anhydrase inhibitors. Bumetanide (0.005-0.1 mmol l-1 carotid plasma) progressively reduced mid-range flow by 52 ± 3.4% (mean ± SEM). Concurrently, saliva [Cl] decreased, [Na] and [HCO3] increased but HCO3 excretion was unaltered. Salivary flow during high-rate cholinergic stimulation was 31 ± 1.1% of the pre-bumetanide maximum. During mid-range stimulation, SITS (0.075 mmol l-1) was without effect whereas 0.75 mmol l-1 stimulated transient increases in fluid output. The higher SITS concentration caused no alterations to flow or electrolyte concentrations during maximal stimulation. Carotid plasma [amiloride] (0.05 mmol l-1) caused immediate falls in flow rate of 20-30% followed by progressive recovery over 25 min to levels above pre-amiloride flow rates despite plasma [amiloride] increasing tenfold. Concurrently, salivary [Na] and [Cl] rose to equal plasma concentrations and [K] fell by 50% indicating blockade of acinar Na/H exchangers and luminal Na channels in the ducts. Increased salivary osmolarity caused the flow recovery. Saliva flow during maximum cholinergic stimulation was reduced by 38-46%. The depression of flow was interpreted as resulting from competition between amiloride and acetylcholine for access to the muscarinic receptors. Plasma [acetazolamide] (0.35-2.5 mmol l-1) did not alter saliva outflow during mid-range or maximum flow regimes whereas salivary [Cl] increased and [HCO3] decreased consistent with reduced anion exchange resulting from inhibition of carbonic anhydrase. Combined with bumetanide, acetazolamide (1.5 mmol l-1) reduced flow by an additional 18-22% relative to bumetanide alone thereby demonstrating that acinar HCO3 synthesis supported a limited proportion of saliva formation and that some HCO3 secretion was independent of carbonic anhydrase activity.

First UK trial of Xenex PX-UV, an automated ultraviolet room decontamination device in a clinical haematology and bone marrow transplantation unit.

BACKGROUND: There is growing interest in the use of no-touch automated room decontamination devices within healthcare settings. Xenex PX-UV is an automated room disinfection device using pulsed ultraviolet (UV) C radiation with a short cycle time. AIM: To investigate the microbiological efficacy of this device when deployed for terminal decontamination of isolation rooms within a clinical haematology unit. METHODS: The device was deployed in isolation rooms in a clinical haematology unit. Contact plates were applied to common touch points to determine aerobic total colony counts (TCCs) and samples collected using Polywipe™ sponges for detection of vancomycin-resistant enterococci (VRE). FINDINGS: The device was easy to transport, easy to use, and it disinfected rooms rapidly. There was a 76% reduction in the TCCs following manual cleaning, with an additional 14% reduction following UV disinfection, resulting in an overall reduction of 90% in TCCs. There was a 38% reduction in the number of sites where VRE was detected, from 26 of 80 sites following manual cleaning to 16 of 80 sites with additional UV disinfection. CONCLUSIONS: The Xenex PX-UV device can offer a simple and rapid additional decontamination step for terminal disinfection of patient rooms. However, the microbiological efficacy against VRE was somewhat limited.

The effect of high rates of vasopressin administration on renal potassium and sodium excretion during potassium loading in the sheep.

1 The influence of potassium loading on the renal excretion of sodium, potassium and solute during high rate vasopressin administration has been investigated in sheep. 2 Adrenalectomized sheep were infused with 0.43 M KCl at 2 ml/min for 2-2.5 hours. Coincident with the rise in plasma potassium concentration, the urinary excretion of sodium, potassium, solute and water was increased as was the reabsorption of solute-free water. The rates of urinary excretion of sodium and potassium, osmolal clearance (COsm) and solute-free water reabsorption (TcH2O) for the first 50 min of potassium infusion were each found to be linearly related to the plasma potassium concentration. 3 After 50 min an infusion of vasopressin at 1 or 4 mu/min was superimposed on the potassium infusion for a period of 30 minutes. The administration of vasopressin was consistently associated with further augmentation of potassium excretion and clearance, of osmolal clearance and of solute-free water reabsorption to values above those anticipated from the pre-vasopressin regression lines for these parameters. Urinary sodium showed a coincident depression in the rate of excretion and clearance during the same period. 4 Thirty to fifty minutes after the cessation of vasopressin infusion the potassium and sodium excretions had returnied to values which approximated the pre-vasopressin relations between plasma potassium and the urinary excretions of these ions. 5 Both rates of vasopressin infusion were equally effective in increasing the potassium clearance. Any differences in clearance between the two rates of vasopressin administration were not statistically significant. 6 The large increments in potassium excretion (averaging greater than 40%) were interpreted as indicating that, when vasopressin is present at high concentrations, the distal tubule is one site of action of the hormone in the nephron of sheep.

Nasal continuous positive airway pressure in decompensated hypercapnic respiratory failure as a complication of sleep apnea.

Cardiopulmonary failure resulting from progression of obstructive sleep apnea (OSA) is treated with endotracheal intubation and mechanical ventilation. This study was conducted to determine whether the use of nasal continuous positive airway pressure (CPAP) would rapidly reverse changes in mental status and hypercapnic acidosis in such patients with decompensated hypercapnic respiratory failure resulting from OSA. Six morbidly obese patients (mean weight, 159 +/- 19 kg) were treated with nasal CPAP and supplemental oxygen. Within 24 h of this treatment, there was a significant increase in pH, from a baseline mean of 7.23 +/- 0.03 to 7.35 +/- 0.01 (p < 0.01), and the mean PaCO2 fell from 80 +/- 4 mm Hg to 64 +/- 4 mm Hg (p < 0.01). In addition, there was a dramatic improvement in mental status within 24 h of therapy with nasal CPAP. None of the patients required intubation and mechanical ventilation. There were no complications attributable to the CPAP delivered by nasal mask. We conclude that CPAP delivered by nasal mask can be safe and effective in rapidly reversing changes in mental status and hypercapnic acidosis in this group of patients with severe respiratory failure, and nasal CPAP obviates the need for endotracheal intubation and mechanical ventilation.

Food restriction and binge eating: a study of former prisoners of war.

Food restriction is correlated with binge eating, but evidence that restriction leads to binge eating is scanty. In this study we investigated postwar binge eating in 67 World War II combat veterans and 198 former prisoners of war. As predicted, binge eating was relatively rare in combat veterans but was significantly more prevalent in veterans who, as prisoners in German prisoner of war camps, lost significant amounts of weight during their captivity. Our data thus support the contention that starvation or dieting seems to precede binge eating.

Enhancing perinatal outcome in homeless women: the challenge of providing comprehensive health care.

Homeless women who are pregnant present a number of challenge to health care providers. As a group, they are at risk for a variety of illnesses that could affect their pregnancies, including sexually transmitted diseases and substance abuse. Poor access to health care, inadequate prenatal care, poor nutrition, and poor housing cause these women to suffer poor birth outcomes. They are more likely to deliver low birth weight infants and have higher rates of infant mortality. It should be understood that homeless pregnant women are a heterogenous group. Generally, they are pregnant adolescents and women in homeless families. Additionally, there are differences within these two groups. The causes of homelessness for these women vary as do their needs during pregnancy. Any provider of health care to the homeless must understand the different situations of these women to deliver directed, effective care.

Effects of fast neutrons on the eye.

The study of 93 eyes receiving neutron irradiation establishes the character of the ophthalmic complications of neutron. Significant changes are produced in the eyelids, conjunctiva, and cornea, but the production of cataract is relatively unimportant. No reaction was seen after neutron treatment that had not already been seen after chi or gamma radiation. That the unavoidable damage is similar to that reported with other forms of radiation, and not worse, is an important finding in view of the statistically significant benefit of neutron treatment to patients in a controlled clinical trial of advanced tumours of the head and neck (Catterall and others, 1975). The observations indicate that the improved cure rates with neutrons are not obtained at the expense of inflicting greater damage to normal structures. This investigation has also shown that the neutron effects of treating these very extensive tumours are acceptable and that, with carefully measured doses, they are predictable. The dose-response relationship in categories of clinical effect for a smaller series of patients, reported in Table 1 of our preliminary communication (Brown and other, 1976), is confirmed.

Social influences on health-risk behaviors among minority middle school students.

PURPOSE: To determine whether parent social influences are associated with health-risk behaviors more than peer social influences among young minority adolescents. METHODS: We conducted a cross-sectional survey of seventh-grade students in a public urban magnet middle school using a survey instrument adapted from the Centers for Disease Control and Prevention Youth Risk Behavior Survey. The sample consisted of all seventh-grade students in the school, and the survey was part of a needs assessment for a school-based health education program. We measured four health-risk behaviors: use of (a) tobacco, (b) alcohol, (c) onset of sexual activity, and (d) marijuana use; and five social influences: (a) parent disapproval of health-risk behaviors, (b) parent modeling of health-risk behaviors, (c) parent monitoring of health-risks, (d) peer disapproval of health risks, and (e) peer modeling of health-risk behaviors. The analyses included measures of the prevalence of health-risk behaviors, bivariate analyses to evaluate relationships between health-risk behaviors and social influences, and regressions analyses to determine the independent associations of the social influences with the four health-risk behaviors. RESULTS: Twenty percent of respondents reported using tobacco, over 50% used alcohol in the past year, 13.3% were sexually active, and 12% reported marijuana use. Parent influences were associated with differences in alcohol use, whereas peer influences were associated with differences in all measured health-risk behaviors: tobacco and alcohol use, sexual activity, and marijuana use. Regression analyses demonstrated that peer social influences were the only measures independently associated with abstinence from tobacco (p < .05), alcohol (p < .01), sexual activity (p < .05), and marijuana use (p < .05). In all analyses, peers emerged as the most consistent social influence on health-risk behavior. CONCLUSION: This study suggests peers and peer group behavior may be better predictors of adolescent health-risk behaviors than parental social influences among young adolescents.

Amylase activity, protein and urea in saliva of the red kangaroo (Macropus rufus).

Parotid and mandibular salivas, produced at flow rates of 0.055 +/- 0.0038 to 4.45 +/- 0.101 and 0.052 +/- 0.0059 to 4.30 +/- 0.072 ml min-1 respectively by intracarotid infusion of acetylcholine or methacholine, were analysed. During acetylcholine stimulation, the protein concentration ranged from 86.4 +/- 10.17 to 235.0 +/- 23.5 mg l-1 in parotid and from 102.9 +/- 11.54 to 379.6 +/- 38.01 mg l-1 in mandibular saliva. The minimum protein concentrations in parotid and mandibular salivas occurred at 0.5 and 1.0 ml min-1 respectively with the concentration rising progressively at lower and higher flow rates. Both glands maintained constant levels of protein during 90 min of sustained stimulation at constant flow rates of 0.5 and 2.0 ml min-1. The optimum pH for salivary amylase activity lay between 7.4 and 7.9 (mean 7.5-7.6). The amylase activity of parotid saliva ranged between 32.2 +/- 3.81 and 94.5 +/- 24.05 mukat l-1 and the activity/protein ratio was similar at all flow rates (mean, 0.39 +/- 0.049 mukat amylase/mg protein). Amylase levels in arterial plasma were constant within experiments but varied from 8.0 +/- 0.07 to 26.4 +/- 0.24 mukat l-1 between experiments, and were always less than corresponding parotid values. Mandibular amylase activities were low, highly variable or often absent. Methacholine-evoked parotid saliva had lower protein concentrations but similar amylase/protein ratios to acetylcholine-stimulated saliva. Urea concentrations in arterial plasma were constant within experiments but varied from 6.71 +/- 0.092 to 14.2 +/- 0.14 mmol l-1 between experiments.(ABSTRACT TRUNCATED AT 250 WORDS)

The effect of transport-blocking drugs on secretion of fluid and electrolytes by the mandibular gland of red kangaroos, Macropus rufus.

Mechanisms of primary fluid formation by macropodine mandibular glands were investigated in anaesthetized red kangaroos using ion-transport and carbonic anhydrase inhibitors. Bumetanide at carotid plasma concentrations of 0.005-0.1 mmol/l progressively reduced a stable, acetylcholine-evoked flow rate of 1.02 +/- 0.024 ml/min to 0.16 +/- 0.016 ml/min (mean +/- SEM). Concurrently, saliva [Na], [Cl] and osmolality decreased, [K] and [HCO3] increased and HCO3 excretion was unaffected. High-rate cholinergic stimulation was unable to increase salivary flow above 12 +/- 1.5% of that for equivalent pre-bumetanide stimulation. Furosemide (1.0 mmol/l) and ethacrynate (0.5 mmol/l) caused depression of salivary flow and qualitatively similar effects on ion concentrations to those of bumetanide. Amiloride (up to 0.5 mmol/l) caused no reduction in salivary flow rates or [Na] but decreased [K] and [Cl] and increased [HCO3]. When compared with bumetanide alone, amiloride combined with bumetanide further augmented [K] and [HCO3] and lowered [Cl], but had no additional effects on Na or flow. At the higher level, 4-acetamido-4'- isothiocyanatostilbene-2,2'disulphonic acid (SITS) (0.05 and 0.5 mmol/l) stimulated fluid output, increased [HCO3] and [protein], and depressed [Na], [K] and [Cl]. Relative to bumetanide alone, SITS given with bumetanide had no additional effects on salivary flow or electrolytes. Methazolamide (0.5 mmol/l) in combination with bumetanide curtailed the decrease in [Cl] and the increases in [K] and [HCO3] associated with bumetanide. The residual methazolamide-resistant HCO3 excretion was sufficient to support 2-6% of primary fluid secretion. It was concluded that secretion of primary fluid by the kangaroo mandibular gland is initiated mainly (> 90%) by Cl transport resulting from Na-K-2Cl symport activity. A small proportion of the fluid secretion (up to 6%) appears to be supported by HCO3 secretion. No evidence was found for fluid secretion being dependent on Cl transport involving Na/H and Cl/HCO3 antiports or on HCO3 synthesis involving carbonic anhydrase.

Enzyme activity in parotid and mandibular saliva from red kangaroos, Macropus rufus.

Parotid and mandibular saliva was obtained from red kangaroos by concurrent acetylcholine isoprenaline stimulation. Salivary proteins were separated by horizontal electrophoresis on either cellulose acetate or starch gels and assessed by specific staining techniques for 23 enzymes commonly found in mammalian tissues and body fluids. Parotid saliva was positive for acid phosphatase, alpha-amylase, carbonic anhydrase, glucose-6-phosphate dehydrogenase, sorbitol dehydrogenase and superoxide dismutase activities. Mandibular saliva was positive for alcohol dehydrogenase in addition to the above six enzymes. The kangaroo salivas lacked activity for alkaline phosphatase, beta-galactosidase and non-specific esterase which occur in saliva from some mammalian species.

The effect of beta-sympathomimetic stimulation on parotid salivation in the red kangaroo (Macropus rufus).

Salivation was stimulated by intracarotid isoprenaline infusion given alone or combined with acetylcholine. By itself, isoprenaline (0.12-1.2 nmol kg-1 min-1) stimulated flow rates of 0.037-0.233 ml min-1 (2.77-10.5 microliters/g gland per min). Salivary Na, Cl, PO4 and total solute concentrations were positively correlated with flow; K, Mg and urea were negatively correlated with flow; and Ca, H+, HCO3, protein and amylase activity were not correlated with flow. Relative to cholinergic saliva, isoprenaline-evoked saliva had higher levels of amylase activity, urea, protein, K, Mg, H+, PO4 and Cl but lower osmolality, Na, Ca and HCO3. At a steady flow (1 ml min-1), isoprenaline infusion (0.3 nmol kg-1 min-1) superimposed on a pre-existing acetylcholine infusion increased salivary amylase activity, protein, urea, K, Mg, Cl and PO4, reduced HCO3 and did not alter Na, Ca, H+ and osmolality. Superimposition of isoprenaline infusion (0.5 nmol kg-1 min-1) on a low-level acetylcholine infusion increased flow rate by 400-900%. Excretion rates of K, Mg, Cl and PO4 were higher and Ca lower than predicted for saliva secreted at equivalent flows during acetylcholine stimulation. Na, H+ and HCO3 were as predicted for the same flow rate under cholinergic stimulation. The simplest coherent interpretation of these data is that isoprenaline affects transport of protein and ions at the end organs, but has little effect on the resting transport characteristics of the striated and excretory ducts of the kangaroo parotid, in accord with the known nerve distribution of this gland.

Blockade of isoprenaline-induced fluid and protein secretion by the mandibular glands of the red kangaroo, Macropus rufus, with selective antagonists.

Selective and non-selective beta-adrenoceptor antagonists were used to block the increases in fluid and protein secretion caused by sympathomimetic stimulation of the mandibular gland of red kangaroos during intracarotid infusion of isoprenaline. Atenolol or ICI118551 at antagonist:agonist ratios up to 300:1 caused increasing but incomplete blockade of fluid secretion and protein release. Both selective antagonists had equal potency and both antagonists were more effective at blocking protein release than at blocking fluid secretion. Consequently, the mechanisms underpinning fluid secretion are more sensitive to beta-sympathomimetic stimulation than those causing protein release. Propranolol at antagonist:agonist ratios of 300:1 was more potent than the selective antagonists, almost totally blocking the increases in fluid secretion and protein release. The data are consistent with the acini of the kangaroo mandibular gland having both beta(1)- and beta(2)-adrenoceptors and with the increased fluid secretion and protein release by isoprenaline being mediated by both receptor subtypes.

Effects of cholinergic stimulation and aldosterone administration on salivary parotid secretion in the brushtail possum, Trichosurus vulpecula.

Parotid salivation was stimulated by infusion of bethanechol chloride into anaesthetized brushtail possums to ascertain maximal flow rates, salivary composition and dietary adaptations of salivary function. Secretion rates for one gland ranged from 5.3 +/- 0.16 to 84.3 +/- 3.20 microliters/min (2.4 +/- 0.07 to 37.8 +/- 1.43 microliters/min per kg body weight). Salivary osmolality (160.8 +/- 15.39 to 248.2 +/- 8.70 mosmol/kg) and the concentrations of Na (63.1 +/- 10.93 to 124.1 +/- 5.52 mmol/l) and HCO3 (19.5 +/- 3.41 to 89.0 +/- 3.19 mmol/l) were positively correlated with flow rate. The concentrations of urea (7.8 +/- 0.64 to 4.6 +/- 0.33 mmol/l), PO4 (2.6 +/- 0.25 to 0.96 +/- 0.10 mmol/l), H+ (46.2 +/- 16.30 to 9.0 +/- 1.51 nequiv/l), K (21.4 +/- 3.73 to 13.7 +/- 2.33 mmol/l), Ca (3.7 +/- 0.53 to 2.2 +/- 0.27 mmol/l) and Mg (0.3 +/- 0.07 to 0.04 +/- 0.007 mmol/l) fell with increasing flow rate. The relations between flow rate and amylase activity (22.6 +/- 10.47 to 10.5 +/- 3.68 mu kat/l), protein concentration (2.7 +/- 0.61 to 1.3 +/- 0.28 g/l), and Cl concentration (62.1 +/- 6.88 to 50.6 +/- 6.37 mmol/l) were inconsistent between experiments. Salivary Na/K ratios were not decreased by infusion of aldosterone (2.2-22.2 nmol/h for 5 h), showing that the gland of Na-replete possums is unresponsive to short-term increases in mineralocorticoids. The low salivary amylase activity, less than that of kangaroos, presumably reflects the interaction of evolutionary history of the possum with its natural low-starch diet.(ABSTRACT TRUNCATED AT 250 WORDS)

Traumatic hemorrhage of occult pheochromocytoma: a case report and review of the literature.

Pheochromocytoma usually presents with gradual onset and mild to moderate symptoms, but may present acutely with severe symptoms. Hemorrhage into pheochromocytoma is a rare cause of acute presentation that is often devastating to patients. We describe the case of a 34-year-old woman with hemorrhage into a previously undiscovered pheochromocytoma following a fall on a patch of ice. This is the first reported case of hemorrhagic pheochromocytoma associated with traumatic injury. Despite removal of the tumor within 18 hours of presentation, the patient suffered severe complications of massive catecholamine excess, including shock, cardiomyopathy, and adult respiratory distress syndrome. Animal studies have shown that early treatment with alpha blockers can prevent some, if not all of these complications. Proper management of hemorrhagic pheochromocytoma should include a high index of suspicion with early diagnosis and treatment with alpha blockers and surgical resection of the tumor when the patient is stable enough to tolerate the procedure.

Chylous ascites: a manifestation of blunt abdominal trauma in an infant.

This report presents an infant in whom a unique case of chylous ascites developed after blunt abdominal trauma. Unfortunately, this case was complicated by Pseudomonas peritonitis, likely from a distant source. Our patient was treated medically and had a good overall outcome.