Accumulation and excretion of long-chain acylcarnitine by rat hearts; studies with aminocarnitine.

During Langendorff perfusion of rat heart with aminocarnitine, long-chain acylcarnitine (LCAC) accumulates in heart cells, from which it is excreted by the heart. The heart function remains intact during this process. The accumulation of LCAC can be inhibited by the simultaneous addition of an inhibitor of the outer membrane carnitine palmitoyl-coenzyme A transferase (CPT-1), indicating that aminocarnitine is a specific inhibitor of the inner membrane isoenzyme (CPT-2). LCAC accumulation is associated with glycogen depletion. After 60 min perfusion with aminocarnitine, electron microscopy shows large multilamellar lipid vesicles, especially in cardiomyocytes, which are depleted in glycogen granula. Multilamellar lipid vesicles are also found in the blood vessels. Extraction of the perfusate shows the presence of LCAC, fatty acid and phosphatidylethanolamine. Morphological analysis with freeze fracturing and thin sectioning furthermore reveals that the sarcolemma is not deteriorated during the export of LCAC to the coronary vessels. Since cardiac structures and functions are intact, LCAC alone is not the clue for ischemic damage. Therefore the present work supports the hypothesis that acidosis rather than LCAC is of primary importance to ischemic damage.     

Biological process of arsenic removal using selected microalgae

In the present investigation, growth of the organisms was reduced due to presence of arsenic (III) and (V) in the culture medium. In comparison to arsenic (V), arsenic (III) had more toxic effect on microalgae. Among the different algal strains, blue green algal species Oscillatoria-Lyngbya mixed culture showed maximum efficiency in removing arsenic (64%) after 21 days of incubation and the same algal species could remove arsenic (III), but 60% after 21 days when incubated in 0.1 mg/l arsenic (III) containing medium. Maximum removal was observed at their exponential growth phase and also so sometime extended to the stationary phase.     

The influence of chemical form and concentration of arsenic on rice growth and tissue arsenic concentration

Arsenic absorption by rice (Oryza sativa, L.) in relation to the chemical form and concentration of arsenic added in nutrient solution was examined. A 4 × 3 × 2 factorial experiment was conducted with treatments consisting of four arsenic chemical forms [arsenite, As(III); arsenate, As(V); monomethyl arsenic acid, MMAA; and dimethyl arsenic acid, DMAA], three arsenic concentrations [0.05, 0.2, and 0.8 mg As L^-1], and two cultivars [Lemont and Mercury] with a different degree of susceptibility to straighthead, a physiological disease attributed to arsenic toxicity. Two controls, one for each cultivar, were also included. Arsenic phytoavailability and phytotoxicity are determined primarily by the arsenic chemical form present. Application of DMAA increased total dry matter production. While application of As(V) did not affect plant growth, both As(III) and MMAA were phytotoxic to rice. Availability of arsenic to rice followed the trend: DMAA<As(V)<MMAA<As(III). Upon absorption, DMAA was readily translocated to the shoot. Arsenic(III), As(V), and MMAA accumulated in the roots. With increased arsenic application rates the arsenic shoot/root concentration decreased for the As(III) and As(V) treatments. Monomethyl arsenic acid (MMAA), however, was translocated to the shoot upon increased application. The observed differential absorption and translocation of arsenic chemical forms by rice is possibly responsible for the straighthead disorder attributed to arsenic.     

Biological and molecular profile of fracture non‐union tissue: current insights

Delayed bone healing and non‐union occur in approximately 10% of long bone fractures. Despite intense investigations and progress in understanding the processes governing bone healing, the specific pathophysiological characteristics of the local microenvironment leading to non‐union remain obscure. The clinical findings and radiographic features remain the two important landmarks of diagnosing non‐unions and even when the diagnosis is established there is debate on the ideal timing and mode of intervention. In an attempt to understand better the pathophysiological processes involved in the development of fracture non‐union, a number of studies have endeavoured to investigate the biological profile of tissue obtained from the non‐union site and analyse any differences or similarities of tissue obtained from different types of non‐unions. In the herein study, we present the existing evidence of the biological and molecular profile of fracture non‐union tissue.     

The influence of arsenic chemical form and concentration on Spartina patens and Spartina alterniflora growth and tissue arsenic concentration

Arsenic (As) uptake by two perennial coastal marsh grasses growing in hydroponic conditions was studied in relation to the chemical form and concentration of As added to nutrient solution. A 4×3×2 factorial experiment was conducted with treatments consisting of four As chemical forms [arsenite, As(III); arsenate, As(V); monomethyl arsonic acid, MMAA; and dimethyl arsinic acid, DMAA], three As concentrations (0.2, 0.8, and 2.0 mg As L^-1) and two plant species (Spartina patens and Spartina alterniflora). Arsenic phytoavailability and phytotoxicity were primarily determined by the As chemical form present in the nutrient solution, though As concentration also influenced both As availability and toxicity. Application of As(V) increased root, shoot and total dry matter production; this positive plant growth response may be linked with P nutrition. Organic arsenicals and As(III) were the most phytotoxic species to both marsh grasses when plant growth was considered. Arsenic uptake and transport in plant were species-specific. Phytoavailability of As followed the trend DMAA MMAA As(V) < As(III). Root and shoot As concentrations significantly increased with increasing As application rates to the rooting medium, regardless of the As chemical form. Upon absorption, inorganic arsenicals and MMAA were mainly accumulated in the root system, while DMAA was readily translocated to the shoot.     

Pharmacokinetic, tissue distribution and excretion of ginsenoside-Rd in rodents

Ginsenoside-Rd (GS-Rd) is one of the major active components of Panax ginseng, and was shown to have the protective effects against several insults. However, we still lack some basic knowledge of GS-Rd, including its pharmacokinetic, tissue distribution and excretion in vivo in experimental animal, such as mice and rats. In this study, HPLC and radioactive tracer assays were performed to determine pharmacokinetic, tissue distribution and excretion of GS-Rd in rodents. After intravascular administration with 20, 50 or 150 mg/kg GS-Rd, the dynamic changes of GS-Rd concentrations in plasma were consistent with a two-compartment model while the concentration of 3H-labeled GS-Rd was rapidly reached the peak in plasma, and distributed to various tissues, among which the highest concentration was observed in the lung.     

Clinical studies with B72.3 in ovarian cancer and probe-guided tumor localization

The present study reports the findings of radiolabeled monoclonal antibody (MoAb) application in the post-operative monitoring of patients with ovarian carcinoma. We studied 40 patients with histologically confirmed ovarian cancer using two radiolabeled MoAbs, ¹³¹I-B72.3 and ¹³¹I-OC125. Antibody scans showed that high uptake of radiolabeled MoAb was consistently associated with presence of disease confirmed by computed tomography, ultrasonography, clinical evolution and in a few cases by second look procedures. Computed tomography could not discriminate well between post-operative fibrosis and tumor lesion especially when localized in the peritoneum. We conclude that radiolabeled MoAbs, computed tomography and serum tumor markers are complementary in the postoperative monitoring of patients with ovarian carcinoma.