A prospective randomised controlled clinical trial comparing somatostatin and vasopressin in controlling acute variceal haemorrhage.

Twenty two patients were entered into a randomised controlled clinical trial comparing the efficacy of somatostatin and vasopressin in controlling acute variceal haemorrhage. Somatostatin was significantly more successful in controlling acute variceal haemorrhage than vasopressin (p = 0.003). Furthermore, no complications were observed during treatment with somatostatin.     

Assessment of the impact of photosystem I chlorophyll fluorescence on the pulse-amplitude modulated quenching analysis in leaves of Arabidopsis thaliana

Photosynthesis Research - In their natural environment, plants are exposed to varying light conditions, which can lead to a build-up of excitation energy in photosystem (PS) II. Non-photochemical...     

Nutritional status and endocrine response to hemorrhage

Hyperglycemia-inducing hyperosmolality has recently been proven beneficial in the maintenance of blood volume and extracellular fluid volume during early hemorrhagic hypotension. Fed animals benefitted from better plasma refill compared with starved ones when subjected to equal blood loss. Using lightly sedated fed and 24-30 h starved rats, hormones with relevance to glucose homeostasis were studied during 90 min of hemorrhagic hypotension of 70 mmHg (1 mmHg = 133.32 Pa). Marked differences in the overall hormonal developments were found between the two groups. In fed rats, insulin and glucagon responses were initially attenuated, while somatostatin increased to an early peak level at 30 min, returning to basal at 90 min. In starved rats, somatostatin increased gradually during the 90 min. Adrenaline release was massive in both groups. Corticosterone showed no increase from basal levels in the fed group during hemorrhage, while starved rats increased their basal level fourfold already at 30 min. These data are presented as evidence that changing nutritional status alters hormonal response to hypovolemic stress.     

A physicochemical and immunologic comparison of the cell growth inhibitory activity of human lymphotoxins and interferons in vitro.

The physicochemical, immunologic, and biologic relationships between humam lymphotoxins (LT) and interferons (IF) present in supernatant fluids from lectin-stimulated peripheral blood lymphocytes (PBL) and a continuous B-lymphoblastoid cell line (PGLC-33h) were analyzed. LT activity obtained from lectin-activated PBL could not be resolved from IF activity by gel filtration chromatography. LT activity eluted in multiple peaks of activity at 70 to 90,000, and 40 to 50,000 m.w., characteristic of alpha and beta LT, respectively. IF activity in these supernatant fluids eluted as a broad band between 35 and 80,000 m.w., also suggestive of molecular heterogeneity. In contrast, this m.w. heterogeneity was not observed in LT and IF activities obtained from the PGLC-33h cell line. LT and IF eluted as separate peaks of activity at 90,000 and 25,000 m.w., respectively. In addition, acid and heat lability of PGLC-33h IF suggested similarity to type II IF. Immunologic studies, with a rabbit anti-alpha class serum that neutralized LT activity from both PBL and PGLC-33h, did not affect IF activity from either of these sources. Supernatant fluids from PGLC-33h cultures were also capable of inhibiting the proliferation of HeLa cells in vitro. The growth inhibitory activity was attributed to LT- and IF-like molecules. This evidence suggests that although cytotoxic and anti-viral activities were due to separate molecules, LT and IF have overlapping biologic activities in their ability to inhibit the proliferation of cells in vitro.     

Cellobiose hydrolysis using acid-functionalized nanoparticles

Mineral acids have been used effectively for the pretreatment of cellulosic biomass to improve sugar recovery and promote its conversion to ethanol; however, substantial capital investment is required to enable separation of the acid, and corrosion-resistant materials are necessary. Disposal and neutralization costs are also concerns because they can decrease the economic feasibility of the process. In this work, three acid-functionalized nanoparticles were synthesized for pretreatment and hydrolysis of lignocellulosic biomass. Silica-protected cobalt spinel ferrite nanoparticles were functionalized with perfluoroalkylsulfonic acid (PFS), alkylsulfonic acid (AS), and butylcarboxylic acid (BCOOH) groups. These nanoparticles were magnetically separated from the reaction media and reused. TEM images showed that the average diameter was 2 nm for both PFS and BCOOH nanoparticles and 7 nm for AS nanoparticles. FTIR confirmed the presence of sulfonic and carboxylic acid functional groups. Ion exchange titration measurements yielded 0.9, 1.7, and 0.2 mmol H⁺/g of catalyst for PFS, AS, and BCOOH nanoparticles, respectively. Elemental analysis results indicated that PFS and AS nanoparticles had 3.1 and 4.9% sulfur, respectively. Cellobiose hydrolysis was used as a model reaction to evaluate the performance of acid-functionalized magnetic nanoparticles for breaking β-(1→4) glycosidic bonds. Cellobiose conversion of 78% was achieved when using AS nanoparticles as the catalyst at 175°C for 1 h, which was significantly higher than the conversion for the control experiment (52%). AS nanoparticles retained more than 60% of their sulfonic acids groups after the first run, and 65 and 60% conversions were obtained for the second and third runs, respectively.