K-edge imaging with the XPAD3 hybrid pixel detector, direct comparison of CdTe and Si sensors.

We investigate the improvement from the use of high-Z CdTe sensors for pre-clinical K-edge imaging with the hybrid pixel detectors XPAD3. We compare XPAD3 chips bump bonded to Si or CdTe sensors in identical experimental conditions. Image performance for narrow energy bin acquisitions and contrast-to-noise ratios of K-edge images are presented and compared. CdTe sensors achieve signal-to-noise ratios at least three times higher than Si sensors within narrow energy bins, thanks to their much higher detection efficiency. Nevertheless Si sensors provide better contrast-to-noise ratios in K-edge imaging when working at equivalent counting statistics, due to their better estimation of the attenuation coefficient of the contrast agent. Results are compared to simulated data in the case of the XPAD3/Si detector. Good agreement is observed when including charge sharing between pixels, which have a strong impact on contrast-to-noise ratios in K-edge images.

The benefits of psychiatric hospitalization for older nursing home residents.

OBJECTIVE: To examine the demographic characteristics and treatment outcomes of nursing home residents admitted to a geropsychiatric inpatient unit. DESIGN: A retrospective cohort design based on an ongoing data base effort. SETTING: The geropsychiatric inpatient unit of the Houston Veterans Affairs Medical Center Hospital. PARTICIPANTS: All admissions to the unit from nursing homes during an 18-month period. MEASUREMENTS: Mini-Mental State Examination, Brief Psychiatric Rating Scale, Hamilton Rating Scale for Depression, Cohen-Mansfield Agitation Inventory, Rating Scale for Side Effects, and Global Assessment of Functioning were administered on admission and discharge. RESULTS: Paired t tests comparing change scores revealed significant decreases in general psychiatric symptoms (P < .001), depression (P < .001), and agitation (P < .001); significant improvement in global functioning (P < .001); with no significant changes in cognitive status (P = .485) or side effects (P = .120). When the patients were subgrouped according to reasons for admission, paired t tests revealed decreases in violence (CMAI Factor 1; P = .000), psychosis (BPRS thought disorder scale; P = .000 and hostility subscale; P < .008), and depression (HAM-D; P = .002). Four patients were discharged to less restrictive environments, all with chronic mental illnesses. CONCLUSION: Inpatient psychiatric hospitalization significantly benefits nursing home residents with and without dementia who are admitted for severe behavior problems.

Seizures induced by penicillin microinjections in the mesencephalic tegmentum.

The location and extension of a convulsive area in the brain stem in cats was determined through penicillin microinjections (0.5-1.0 microl) of a concentrated sodium penicillin solution (500 IU/microl), stereotactically oriented to multiple structures, in fully awake animals, partially restrained through a rod fixation system that avoided pain, allowed the observation of clinical seizures and simultaneous recording of EEG, EMG and multiple unit activity (MUA) from the injected site and the motor cortex (Cx). Clinical and EEG seizure patterns in relation to the injected sites and penicillin doses were studied in another group of animals using doses from 12.5 IU/0.1 microl to 125 IU/1.0 microl. The time relationship between muscular clonus, EEG spikes and MUA at the injected site and Cx were analyzed. The only area in which penicillin induced seizures was the mesencephalic tegmentum (MT). The amount of penicillin but not the stereotactic coordinates determined the seizure type. MT EEG and MUA paroxysms anticipated clinical seizure and Cx EEG spikes. When Cx EEG appeared, they were accompanied by an increase in MUA beginning in the Cx and EMG, followed by significant increase in MT MUA. The sequence of events suggest that MT seizure activity propagates via alternative pathways not involving direct reticulospinal or pyramidal tract pathways.

Xanthorrhizol induces endothelium-independent relaxation of rat thoracic aorta.

Xanthorrhizol, a bisabolene isolated from the medicinal plant Iostephane heterophylla, was assayed on rat thoracic aorta rings to elucidate its effect and likely mechanism of action, by measuring changes of isometric tension. Xanthorrhizol (1, 3, 10, 30 and 100 microg/mL) significantly inhibited precontractions induced by KCI-; (60mM), noradrenaline (10(-6) M) or CaCl2 (1.0 mM). Increasing concentrations of external calcium antagonized the inhibitory effect on KCl-induced contractions. The vasorelaxing effect of xanthorrhizol was not affected by indomethacin (10 microM) or L-NAME (100 microM) in intact rat thoracic aorta rings precontracted by noradrenaline, which suggested that the effect was not mediated through either endothelium-derived prostacyclin (PGI2) or nitric oxide release from endothelial cells. Endothelium removal did not affect the relaxation induced by xanthorrhizol on rat thoracic aorta rings, discarding the participation of any substance released by the endothelium. Xanthorrhizol inhibitory effect was greater on KCI- and CaCl2-induced contractions than on those induced by noradrenaline. Xanthorrhizol inhibitory effect in rat thoracic aorta is likely explained for interference with calcium availability by inhibiting calcium influx through both voltage- and receptor-operated channels.

Indirect immunofluorescent assay (IFA) in buffy coat as a rapid diagnostic test for invasive candidiasis.

In order to have a diagnostic test for invasive candidiasis, an immunofluorescent assay (IFA) in buffy coat was developed and evaluated. This test was compared to buffy coat culture and blood culture. The study was divided into two parts: evaluation of the diagnostic test in a rabbit model, and for diagnosis in patients at high risk for invasive candidiasis. Part I: Rabbits were experimentally infected. Of 13 rabbits with disseminated candidiasis blood was drawn from central venous catheter and from peripheral veins. From catheters, Candida was detected in 13/13, 10/13 and 8/13, by buffy coat culture, IFA, and blood culture, respectively. From peripheral veins, Candida was detected in 10/10 by buffy coat cultures, in 6/10 by IFA and in 3/10 by blood cultures. The gold standard was histopathological diagnosis; sensitivity for IFA was 60% with peripheral blood and 76% with catheter blood samples. Part II: IFA and blood cultures were compared in clinical samples from hospitalized children. Forty patients were included. Candida was isolated from blood cultures in four patients whereas IFA detected Candida in 22 patients. Differences were statistically significant (p < 0.05). We conclude that IFA in buffy coat smears is a reliable test to detect candidemia, and would be a useful tool to help physicians with treatment decisions with amphotericin B.

Galphimia glauca organic fraction antagonizes LTD(4)-induced contraction in guinea pig airways.

Galphimia glauca is used for the treatment of asthma and allergies in Latin American traditional medicine. The ethylacetate fraction from its aerial parts was assayed for bronchoconstriction induced by antigen and several agonists in guinea pig tracheae. The organic fraction significantly inhibited the contractile response to ovalbumin in tracheae from sensitized guinea pigs, and significantly and selectively inhibited the bronchoconstriction induced by leukotriene D(4) (LTD(4)). The relative potency of the ethylacetate fraction of G. glauca to produce a concentration-dependent rightward shift of LTD(4) concentration-response curve was similar to that reported for SK&F 104353, a well-known competitive LTD(4)-antagonist.

Hormonal interelationships and physiological responses of lactating dairy cows to a shade management system in a subtropical environment.

Lactating cows (n = 64) were assigned randomly to shade or no shade treatments for a continuous trial (20 wk) during summer of 1976. Respirations/min and rectal temperatures were higher for no shade cows. Dry matter forage intake was 9.7% higher for shade cows, whereas water intake was 19% greater for no shade cows. Milk yield and conception rates were higher for shade managed cows. Mean plasma corticoid concentrations were high throughout the entire estrous cycle in no shade compared to shade cows (13.04 > 8.72 ng/ml). No shade cows had higher progesterone and LH concentrations, and a lower estradiol to progesterone ratio during the cycle. Results indicated that endocrine changes were indicative of recurring estrous cycles in thermal stressed lactating dairy cows. However, alterations in water intake and thermoregulation of stressed cows were associated with decreased fertility and milk production, and changes in steroid concentrations that may reduce uterine blood flow.

The effects of dietary protein on age and weight at the onset of puberty in Brown Swiss and Zebu heifers in the tropics.

The effects of dietary protein level on age and weight at onset of puberty were studied in the Mexican tropics using 12 Brown Swiss and 12 Zebu heifer calves in a completely randomized block design. The calves were weaned at 3 mo of age. They were confined in individual pens and fed either an adequate protein (12.8%) or a high protein (16.4%) diet ad libitum through the onset of puberty, which was defined as the first ovulation. To detect the first ovulation, heifers were palpated at 8 mo of age and then every 2 wk. At the detection of a developing follicle or any behavioral sign of estrus, they were palpated daily. Ovulation was confirmed by palpation of a corpus luteum. A blood sample for the determination of plasma progesterone concentration was taken with each palpation. There was a significant effect of breed on age at the onset of puberty, which was 9.4 and 12.3 mo for the Brown Swiss and Zebu heifers, respectively. Weight at puberty was 233 kg, independent of breed. Dietary protein had no effect on the onset of puberty. Brown Swiss heifers reach puberty earlier than Zebu heifers. Heifers in the tropics fed according to NRC recommendations reach puberty at ages comparable to those in temperate climate. This suggests that, if managed properly, calving age for Brown Swiss and Zebu heifers can be 24 and 27 mo, respectively. This is a considerable improvement from 36 to 48 mo of age now common in the area of study.

Hormonal responses of lactating dairy cattle to TRH and ACTH in a shade management system within a subtropical environment.

Lactating cows (64) were balanced by breed (54 Holstein and 10 Jersey) and assigned randomly to shade (S) or no shade (NS) management treatments for a continuous 20 wk trial beginning 5-5-76. A sub-sample of Holstein cows, five S and five NS, were fitted with jugular catheters 84 days after initiation of experiment. Thyrotropin Releasing Hormone (TRH; 100 mug) was administered intravenously at 1200 h to evaluate prolactin responses. Two days later each cow received intravenously 200 IU of ACTH at 1100 h to compare acute corticoid responses to ACTH. Mean prolactin response to TRH was greater for NS cows (291 vs 169 ng/ml; P < .01) as was peak plasma concentrations at 20 min (467 vs 267 ng/ml; P < .01). Mean corticoid response to ACTH injection was less for NS cows (52 vs 70 ng/ml; P < .10). Corticoid concentrations of plasma in both treatments had declined 65% by 7 h postinjection. These endocrine differences may be associated with thermoregulation and/or metabolic adjustments of cows exposed to different environmental systems of management during a seasonal period of thermal stress.

[Amikacin in single daily doses in children with fever]. / Amikacina en dosis única diaria en ninõs con fiebre.

A randomized clinical trial was performed in children with cancer, fever and neutropenia, to evaluate the efficacy of amikacin once daily versus thrice daily dosing plus carbenicillin in both groups. Fifty patients were included, 25 patients in group A who received amikacin once daily and 25 in group B who received amikacin thrice daily. No intergroup differences were observed, i.e., fever diminished in a median of 6 days (2-8 days) vs. 7 days (3-12 days) in groups A and B respectively (p = 0.37);clinical improvement was observed in a median of 6 days (3-10 days) vs 7 days (2-14 days) (p = 0.68). One patient in group A and two in B died. The peak levels of amikacin on the 7th day of treatment were 10-60 and 7-25 micrograms/mL in groups A and B respectively, and the serum creatinine levels were 0.3 - 0.7 for group A and 0.2 - 0.8 mg/dL for group B; none of the patients presented a creatinine above 40% of the basal value. Three patients of group A had amikacin levels higher than 40 micrograms/mL without increasing the creatinine levels; our observations do not suggest that toxicity is higher. We conclude that the administration of aminoglycoside once daily seems to be as effective as the traditional dosing.

Uranium removal from water using cellulose triacetate membranes added with activated carbon.

Ultrafiltration removal of uranium from water, with composite activated carbon cellulose triacetate membranes (AC-CTA), was investigated. The filtrate was provided by uraninite dissolution with pH=6-8. Removal efficiencies were calculated measuring solutions' radioactivities. Membranes were mainly characterized by microscopy analysis, revealing iron after permeation. Uranyl removal was 35±7%. Chemical speciation indicates the presence of (UO(2))(2)CO(3)(OH)(3)(-), UO(2)CO(3), UO(2)(CO(3))(2)(2-) and Fe(2)O(3)(s) as main compounds in the dissolution, suggesting co-adsorption of uranium and iron by the AC during filtration, as the leading rejection path.