Comparison of two methods of altering blood pressures for assessing neonatal cerebral blood flow autoregulation

The cerebral blood flow of newborn lambs at reduced and elevated arterial blood pressures, induced by intravenous infusion of sodium nitroprusside and phenylephrine hydrochloride as well as blood withdrawal and reinfusion, were compared. Both blood withdrawal and sodium nitroprusside infusion reduced mean arterial pressure from 83 to 60 mmHg (1 mmHg = 133 Pa). Reinfusion of blood increased arterial pressure to 94 mmHg. Phenylephrine hydrochloride infusion increased arterial pressure to 102 mmHg. The cerebral blood flows at corresponding arterial pressures were similar (coefficient of correlation = 0.88, P less than 0.01). Cerebral blood flow before and after infusion of phenylephrine hydrochloride and sodium nitroprusside into the brain via the carotid artery did not change. The results indicate that blood-borne phenylephrine hydrochloride and sodium nitroprusside, in concentrations that would alter arterial blood pressure significantly from its resting level, do not change cerebral blood flow directly.     

Overview of the advances in plant microbial fuel cell technology for sustainable energy recovery from rhizodeposition

In plant microbial fuel cells (p-MFCs) electrochemically active microbes present around the plant root convert rhizodeposits or the organic matter into electrons, protons, and CO₂. This work covers the increasing trend in research with p-MFCs with their mechanism of operation. Different plant species and their selection criteria are also covered. Furthermore, the long-term evaluation of such systems with its cost effectiveness and commercial and environmental perspectives are also presented. A critical aspect for bioelectricity production is the photosynthetic pathway of the plant. Additionally, the microbial communities and reactor configurations employed across different capacities are also reviewed. The challenges with bioelectricity production and the opportunity for developing p-MFCs in conjunction with traditional MFCs are also covered. These electrogenic reactor systems harness bioelectricity without harvesting the plant and has the capacity to utilize this energy for remote power applications.     

Effects of aspirin and paracetamol on ATPases of human fetal brain: an in vitro study

In vitro effects of aspirin and paracetamol at the doses 200, 400, 600, 800 nmole/mg protein on ATPases activity were studied in the cerebrum and cerebellum of human fetus covering the age range from 10 weeks to 32 weeks of gestation. Both aspirin and paracetamol inhibit Na+K+ ATPase and Mg2+ ATPase in a dose dependent manner. The inhibition of Na+K+ ATPase and Mg2+ ATPase activity which may affect the release and uptake of biogenic amines in CNS, hinders the maturation of human fetal brain.     

A Rapid Method for Isolating Mutants of Bacillus subtilis Producing Increased or Decreased Amounts of the Antibiotic, Mycobacillin

S ummary : A simple, rapid and efficient technique is described for the isolation of mutants of Bacillus subtilis in which the synthesis of mycobacillin, an antifungal antibiotic, is blocked. Suspensions of a chosen culture were subjected to ultraviolet radiation and then plated; colonies failing to produce antibiotic were located by flooding the incubated plates with agar seeded with sensitive fungi such as Candida albicans and Aspergillus niger . The method is also applicable for the isolation of high potency strains.     

Modulation of ASK1 expression during overexpression of Trx and HSP70 in stressed fish liver mitochondria

Mitochondrial heat shock protein 70 (mtHSP70) is found to play a primary role in cellular defense against physiological stress like exposure to environmental contaminants and helpful in the maintenance of cellular homeostasis by promoting the cell survival. In the present investigation, the environmental-stress-induced increase in mtHSP70 levels along with the quantification of apoptosis signal regulating kinase 1 (ASK1) and thioredoxin (Trx) were measured in the liver mitochondria of grey mullets (Mugil cephalus) collected from the polluted Ennore estuary and the unpolluted Kovalam estuary for a period of 2 years. The results showed elevated lipid peroxide (LPO) and decreased total antioxidant capacity along with the decrease in mitochondrial viability percentage. Mitochondrial HSP70, ASK1, and Trx levels were increased under this stress condition. A 42% increase in LPO levels and 18% decrease in mitochondrial survivality were observed in the polluted-site fish liver mitochondria when compared to the results of unpolluted estuary. We also report that, under observed oxidative stress condition in Ennore fish samples, the ASK1 levels are only moderately elevated (13% increase). This may be due to mitochondrial-HSP70-induced adaptive tolerance signaling for the activation of Trx (22% increase) which suppresses the ASK1 expression thereby promoting the cell survival that leads to the maintenance of the cellular homeostasis.     

Pyridine and other coal tar constituents as free radical-generating environmental neurotoxicants

Summary We have tested the hypothesis that chronic exposure to the principal constituents of the aqueous fraction of coal tar extracts can lead to the in vivo formation of substances which may produce neurological damage as the result of free radical generation and lipid peroxidation, these may be involved in the etiology of some neurological disorders. Artificial mixtures of the aqueous fraction of coal tar extracts were given in low concentrations to pigmented mice in their drinking water over a 3-month period. This resulted in significant increases in lipid peroxidation in the striatum, cerebellum and liver of the mice under test, the rank order being striatum > cerebellum > liver. These results are compatible with the possibility that coal tar emissions (as would be recovered or liberated in the burning, refining or beneficiation of coal) constitute a potential source of neurotoxicants with a predilection for damaging the nigrostriatal neuronal pathway. Our observations may thus have identified an important and hitherto unsuspected environmental source of neurotoxic chemicals, a possibility consistent with the proposed involvement of an environmental chemical factor in Parkinson's disease and perhaps in other neurological disorders.     

Morphological and biochemical effects of gentamicin and cyclosporin-a on urinary cell phospholipids and phospholipases in man

The morphology, lipid composition, and activity of sphingomyelinase (E.C. 3.1.4.12) and phospholipases A (E.C. 3.1.1.32) and C (E.C. 3.1.4.3) were studied in the urinary cells from four normal subjects, four patients receiving gentamicin (G), and four patients receiving cyclosporin-A (CsA). We report that abnormal urinary excretion of proximal tubular cells occurred in patients receiving G and CsA. Membrane-enclosed sudanophilic material and numerous vacuoles were found in the cytoplasm of the proximal tubular cells from both patients receiving G and those receiving CsA. Patients receiving G shed higher levels of phosphatidylcholine (PC), phosphatidylethanolamine (PE), and sphingomyelin (SM) in the order of 78%, 38%, and 30% relative to normal. In contrast, the excretions of phosphatidylinositol (PI) and PC were 50% and 30% lower, respectively, in patients receiving CsA as compared to control. Sphingomyelin levels, however, were moderately elevated in these patients' urinary renal tubular cells. The activity of acid sphingomyelinase was one half the normal level in the cells of patients receiving G and CsA. The most striking result was a tenfold decrease in the activity of neutral sphingomyelinase in patients receiving G. In contrast, the activity of neutral sphingomyelinase in patients receiving CsA was similar to control. Phospholipase A activity was decreased and increased 35% and 15%, respectively, in urinary proximal tubular cells from patients receiving G and CsA. We conclude that deficient neutral sphingomyelinase activity precedes phospholipid (PL) overloading and gross pathological changes in patients receiving gentamicin but not in patients receiving cyclosporin-A.     

Fungi Growing on Jute Fabrics Deteriorating under Weather Exposure and in Storage

Special media suitable for the isolation of fungi growing on jute were developed. Species that would better resist sunlight, such as organisms with dark hyphae and spores or closed fruit bodies, predominated on weather-exposed fabrics. Several strongly cellulolytic organisms not previously implicated in fiber decomposition were isolated from this source. On the other hand, the fungi obtained from jute materials damaged in storage were mostly of the familiar types. Most of the newly isolated fungi are generally missed on ordinary media, but they probably play an important role in the natural decomposition of jute materials.