Histochemical observations on the seasonal fluctuations in the follicular atresia and interstitial gland tissue in the house sparrow ovary

A histochemical study has been made of seasonal fluctuations in the follicular atresia and interstitial gland tissue with the ovarian cycles of the house sparrow (Passer domesticus). The atresia of primordial oocytes forms the predominant feature of the quiescent-winter ovary. The building up of interstitial gland tissue of thecal origin. which precedes the breeding activity, is closely related to the atresia of previtellogenic follicles of variable sizes. Interstitial gland cells which accumulate lipid droplets consisting of cholesterol, and/or its esters, triglycerides and some phospholipids, are the steroid secretors. The possible functional significance of different-sized follicular atresia in relation to follicular growth and breeding activity is discussed.     

Depressive disorders in Vietnam returnees

Localization and characterization of different lipids in the cellular constituents of the skin of Heteropneustes fossilis has been made using several histochemical techniques. High contents of cholesterol, its esters and phospholipids have been correlated with the metabolically active state of the basal cells undergoing cell proliferation and differentiation. The polygonal cells in the outermost layer of the epidermis, though rich in phospholipid contain small amounts of cholesterol and its esters. This has been correlated with the metabolically less active state of theses cells. Neutral lipids and phospholipids in the polygonal cells of the outermost layer may contribute to the contents of surface slime and act as an efficient barrier for the penetration of water through the skin. The deposits of neutral lipids in the subcutis may provide energy during the period of fasting, act as a barrier for water diffusion through the skin and serve as shock absorbing pads protecting the fish from mechanical injury.     

Studies on phospholipids of different mutants of Salmonella minnesota

Lipid composition of the cells of smooth (S form) and core-defective rough mutants (Ra, Rb & Re) of Salmonella minnesota has been studied. The readily-extractable lipids (RELs), acid-extractable lipids, and polar and nonpolar phospholipids have been analysed. Fatty acid composition of the different fractions containing phospholipids and other neutral lipids have been determined by GLC and GC-MS techniques. Phosphatidyl glycerol (PG), phosphatidylethanolamine (PE) and diphosphatidyl glycerol (DPG) were the major phospholipids present in all the strains. The major saturated fatty acid found was C16:0, and unsaturated fatty acids were, C16:1 and C18:1. Cyclopropane fatty acids, C17cy and C19cy, were also present in small amounts. Increased amounts of REL and unsaturated fatty acids were found in the mutants compared with the smooth strain. The amount of PG and PE decreased and DPG increased in the mutant strains.     

Lipid components of aminoacyl-tRNA synthetase complex in eukaryotes and their function

This review includes data about lipids composition of eukariotic high molecular complex of aminoacyl-tRNA synthetases under normal conditions and under the effect of ionizing radiation. The role of different lipids in formation of the structure of high molecular complex and functioning is discussed. The role of different groups of phospholipids, prostaglandins in providing the normal work of high molecular complex and some synthetases in control and pathological state is considered. A conclusion has been made that different groups of lipids composed the high molecular complex aminoacyl-tRNA synthetases. Some of them play structural role and other (prostaglandins, some phospholipids) are the regulatory components of the complex.     

Lipid peroxidation in low density lipoproteins from human plasma and egg yolk promotes accumulation of 1-acyl analogues of platelet-activating factor-like lipids

Oxidative modification of low density lipoprotein (LDL) is known to be a key event for induction of atherosclerosis. However, there has been little progress in structural elucidation of oxidized lipids, especially oxidatively fragmented phospholipids retaining a glycerol backbone. In this study, we found that LDL derived from egg yolk has no platelet-activating factor (PAF) acetylhydrolase activity, and that prolonged incubation of egg yolk LDL with Cu2+ resulted in the formation of various PAF-like lipids: 1-acyl type phosphatidylcholines with an sn-2-short-chain dicarboxylate or monocarboxylate group. Only a very small amount of the PAF-like lipid having an sn-2-short-chain monocarboxylate group was detected by gas chromatography-mass spectrometry in Cu(2+)-oxidized LDL from human plasma with high PAF-acetylhydrolase activity, which has been reported to hydrolyze PAF-like lipids to lysophosphatidyl-cholines. Preincubation of plasma LDL with diisopropyl fluorophosphate dose-dependently inhibited PAF-acetylhydrolase activity, resulting in accumulation of the PAF-like lipids when the LDL was oxidized with Cu2+. As well as PAF and lysophosphatidylcholines, several PAF-like lipids were found to inhibit [3H]thymidine incorporation into cultured vascular smooth muscle cells derived from rat aorta. The possible formation of PAF-like lipids by lipid peroxidation in LDL is discussed as well as its possible significance for induction of atherosclerosis.     

The increasing use of paraquat as a suicidal agent

The distribution of neutral lipids and phospholipids in Hymenolepis microstoma has been studied using Fettrot, Sudan Black B, Sudan IV and copper phthalocyanin staining techniques. In the cysticercoid, neutral lipids are found in the outer membrane, the lining of the cysticercoid cavity, the tegument of the larval worm and the calcareous corpuscles. A decreasing gradient of phospholipids is found starting from the acellular layer, through the circular fibrous layer, the longitudinal fibrous layer, the adjacent dense zone and ending with the lining of the cysticercoid cavity. Phospholipids are also found in the calcareous corpuscles and the tegument of the larval worm. In the young adult (3 days p.i.) fat globules are first seen to accumulate in the last 2-3 proglottids. Until the 6th day p.i. they are found in the posterior third of the worm, surrounding developing gonads, but mostly concentrated along the transverse line. The mature proglottids contain fat, (a) in both granular and globular forms: in the folds of the uterus, sperm ducts, cirrus pouch and tegument (proximal cytoplasm), (b) in a diffuse form: in the vitellaria, ovary, testes and the tegument (distal cytoplasm). Pre-gravid and gravid proglottids show the largest fat globules. From the cleaving embryo to the fully developed oncosphere the concentrations of neutral lipids and phospholipids vary in form, intensity and location. In all strobilar forms of the parasite neutral lipids and phospholipids are found in the tegument and calcareous corpuscles. Although in H. microstoma lipid droplets are found in the excretory canals, all lipids in the proglottids are not absolutely waste products. From the results it would appear that they play a role in the maturation of gonads and transformation of the fertilized ovum to the oncosphere.     

Effect of mutagens on RNA-containing phages and its infectious RNA. VII. Genetic nature of morphologic mutants of RNA-containing phage MS2

Temperature-sensitive "leaky" mutants of phage MS2 having white dense ring around negative colonies are described. As these mutants are used for quantitative genetic studies, the white ring presents interest. Typical mutant 40 is used as a model for investigation. Light microscopy has shown, that cells from white ring zone have spore-like inclusions, which determine the characteristic structure of surrounding mutant negative colonies. Cytochemical reactions for the presence of glicogen, lipids, volutin, nuclear material and spores were negative. Electrone microscopy of negatively stained samples and ultrathin sections has revealed that cells from white ring zone, unlike phage-infected wild type cells, have two types of electron dense inclusions: 1) crystalline structures formed with great number of closely packed mature phage particles, and 2) large amorphic bodies. Electrone microscope-cytochemical data showed that inclusions remain intact under treatment of ultrathin sections of white zone ring with DNase and perchloric acid, while nuclear material was completely destroyed. Amorphic bodied were completely destructed after the treatment with RNase, while nuclear material and crystalline phage aggregated remained unchanged. Therefore, amorphic bodies consist of RNA, which has not been used to form virions. Single cycle of the development of mutant 40 at 37 degrees and 43 degrees C and under the temperature of incubation 37 degrees leads to 43 degrees C and 43 degrees leads to 37 degrees C in the course of intracellular reproduction is investigated. Influence of the phage on growth on infected culture is studied. The data obtained draw to a conclusion that the impaired function belongs to cystron protein of the phage membrane. As certain mutations in this cystrone of RNA-containing phage result in the depression of cystrone RNA polymerase, it is supposed that the formation of RNA containing bodies in infected cells, determining the formation of white rings in NA, together with cristalline aggregates of cells, is a result of mutation damage of cystrone protein of the phage MS2 membrane.     

Histochemical features of the adrenal glomerulor zone 30 days after exposure to NPK fertilizer

Sexually mature, male, Wistar rats lived for 30 days in a workshop of an NPK artificial fertilizer factory and were subjected to the effects of different chemical matters used in the synthesis of the fertilizer. After that time period, the experimental animals were sacrificed on the same day with the control ones, in the morning hours. The histochemical characteristics of the adrenal glomerular zone were studied. The results obtained show an increased content of the following lipid substances in the cells of the glomerular zone of the experimental animals: neutral lipids, triglycerides and phospholipids. The content of nucleic acids was also changed. The quality of fat substances was altered in the experimental rats. The total appearance of the glomerular zone gives the impression of an intensified activity.     

The lipase from Staphylococcus aureus. Expression in Escherichia coli, large-scale purification and comparison of substrate specificity to Staphylococcus hyicus lipase

The genes coding for the mature part of the lipases from Staphylococcus aureus NCTC8530 and Staphylococcus hyicus have been cloned and overexpressed in Escherichia coli as fusion proteins with an N-terminal hexa-histidine tag. The enzymes accumulated in the cytoplasm and were purified using sequential precipitation with protamine sulphate and ammonium sulphate, followed by metal-affinity and hydroxyapatite chromatography. The yield of pure lipase was 4.5 mg/g wet cells for S. aureus lipase and 13 mg/g for S. hyicus lipase. The purified enzymes need calcium for activity, albeit with different affinities, and a low residual activity was found in the absence of calcium. In contrast to S. hyicus lipase, not only strontium but also barium can replace calcium with full retention of activity of S. aureus lipase. Whereas S. hyicus lipase is optimally active at pH 8.5, the optimum pH for enzymatic activity for S. aureus lipase was found to be pH 6.5. The S. aureus lipase has a narrow substrate specificity: short-chain triacylglycerols and acyl esters of both p-nitrophenol and umbelliferone are readily degraded, whereas medium- and long-chain lipids, as well as phospholipids, are poor substrates. In contrast, S. hyicus lipase prefers phospholipids as substrate and hydrolyses neutral lipids irrespective of their chain length. The results are discussed in view of the large sequence similarity between both lipases.     

Lipids from the African swine fever virus

The lipids of highly purified african swine fever virus (ASFV) propagated in porcine bone marrow cells were observed to contain 25.6% phospholipids, 9.7% monoglycerides, 14.1% cholesterol, 17.8% free fatty acids, 14.4% diglycerides, 13.6% triglycerides, and 6.7% cholesterol ethers. Diethyl ether extracts mono-, di-, triglycerides, free fatty acids, 50% of cholesterol and cholesterol ethers, and 25% of phospholipids from the virus. Analysis of the 14C-sodiumacetate incorporation into viral, cellular and plasmatic membrane lipids has shown that (a) different strains of ATV ASFV have identical composition; (b) viral lipid composition is determined by lipid composition of the infected cells plasmatic membrane; (c) the viral lipid composition is influenced by cells used for propagation of the ASFV.     

Studies on the testis of the camel (Camelus dromedarius). III. Histochemical observations

The histochemical localization of carbohydrates and lipids and some oxidative, hydrolytic and steroid-linked enzymes has been studied in the testis of the camel with particular reference to the effect of the season on the distribution of these substances. PAS-positive, but diastase-resistant, material was seen mainly in the wall of blood vessels and in the boundary tissues of the seminiferous tubules, tubuli recti and rete testis. Clear cyclical changes were seen for glycogen in the lining epithelium of the seminiferous tubules. Glycogen was most abundant in early stages and very scanty or absent in the late stages of the cycle of the seminiferous epithelium. Numerous small lipid droplets were seen in the interstitial cells and towards the lumen of the seminiferous tubules that contain elongate spermatids or spermatozoa. Large lipid droplets were also demonstrable in the basal layer of the seminiferous epithelium and in the cytoplasmic debri. Alkaline phosphatase was demonstrated in the boundary tissues of the seminiferous tubules, tubuli recti and reti testis and in the cells bordering the lumen of the seminiferous tubules. Succinate and lactic dehydrogenases showed similar patterns of distribution in the interstitial elements and intratubularly. delta5-3beta hydroxysteroid dehydrogenase was exclusively demonstrated in the interstitial cells. 17beta-hydroxysteroid dehydrogenase could not be demonstrated. The season seems to have no effect on the distribution of all these substances. The possible significance of all these findings is discussed.     

Effect of L-carnitine on lipid peroxidation and lipid composition in blood serum in hemic hypoxia]

Sodium nitrite has been studied for its effect on lipid metabolism of Wistar line rats. It is shown that a single administration of sodium nitrite in account 5 mg per 100 g of the body weight results in the intensification of lipids peroxidation, hyperbetalipoproteinemia, hypertriglyceridemia, hypercholesterolemia and to the decrease of the coefficient phospholipids/cholesterin/. Prophylactic administration of carnitine chloride in account of 20 mg per 100 g of the body weight stabilizes the level of lipids peroxidation, decreases concentration of total lipids, triglycerides, total cholesterin, phospholipids, lipoproteids of low and very low density, in the rat blood serum, normalizes the coefficient phospholipids/cholesterin.     

A zebrafish Id homologue and its pattern of expression during embryogenesis

Schistosoma mansoni is known to be unable to synthesize fatty acids and sterols de novo, but the parasite is capable of synthesizing phospholipids and triacylglycerols from precursors obtained from the host. The present study focuses on the dynamics of the incorporation of fatty acids in adult parasites. This study showed that fatty acids were rapidly metabolized into complex lipids and that oleate (18:1) was efficiently converted to eicosenoate (20:1) by chain elongation, whereas palmitate was not elongated at an appreciable rate. This chain elongation mainly involved fatty acids that were previously esterified to complex lipids. Furthermore it was shown that in adult parasites triacylglycerols do not serve as fatty-acyl donors in phospholipid synthesis as had been suggested to be the case in schistosomula, because: (1) Immediately after pulse-labelling the specific activity of fatty acids in phospholipids was higher than in triacylglycerols; and (2) the specific activity of eicosenoate, which had been formed by chain elongation of incorporated oleate. was higher in phospholipids than in triacylglycerols. Fatty acids that were esterified to phospholipids had a high turnover, in contrast to fatty acids esterified to triacylglycerols, which persisted for extended periods of time in this lipid class (days rather than hours).     

Random versus selective membrane phospholipid oxidation in apoptosis: role of phosphatidylserine

The formation of reactive oxygen species has been associated with apoptosis. To assess the role of lipid peroxidation in apoptosis, we used 2,2'-azobis(2,4-dimethylisovaleronitrile) (AMVN) to generate peroxyl radicals within cellular membranes of HL-60 cells. cis-Parinaric acid (cis-PnA) metabolically integrated into phospholipids of HL-60 cells was used as a probe to assess the extent of lipid peroxidation within specific phospholipid classes. Within 2 h, AMVN (500 microM) randomly oxidized more than 85% of cis-PnA contained in all major classes of phospholipids. AMVN-induced lipid peroxidation was followed by apoptosis as determined by nuclear condensation, DNA fragmentation, and annexin V binding to externalized phosphatidylserine (PS). Fluorescamine derivatization of external aminophospholipids revealed that PS, but not phosphatidylethanolamine, was externalized. The vitamin E analogue, 6-hydroxy-2,2,5,7,8-pentamethylchromane (PMC), inhibited overall oxidation of cis-PnA in phospholipids by more than 85%. Not all phospholipids, however, were equally protected. Phosphatidylcholine, phosphatidylethanolamine, phosphatidylinositol, and sphingomyelin were nearly completely protected by PMC, while oxidation of PS was unaffected in whole living cells. The insensitivity of PS to PMC was not an intrinsic property because PMC protected all lipids equally during AMVN oxidation of liposomes prepared from cis-PnA-labeled cells. The potential role for PS oxidation in apoptosis was further suggested by the faithful execution of apoptosis following coexposure of cells to AMVN and PMC.     

Application of muscle microdialysis to evaluate the concentrations of the fluoroquinolones pazufloxacin and ofloxacin in the tissue interstitial fluids of rats

Muscle microdialysis has been used to determine the unbound concentrations of the fluoroquinolones, pazufloxacin and ofloxacin, in tissue interstitial fluids (Cisf,u) of rats under steady state conditions. Cisf,u was estimated from the concentration in dialysate and the in-vitro permeability rate constant by the extrapolation method based on the clearance concept. Paper-disks were inserted under the abdominal skin of rats, and the drug concentrations in the fluids penetrating into the disks (Cdisk) were measured and compared with Cisf,u. The Cisf,u of pazufloxacin and ofloxacin in muscle were close to their unbound concentrations in the venous plasma; these were 75.3% and 77.1%, respectively, of the total concentrations in plasma at the steady state. The Cdisk of pazufloxacin and ofloxacin were also close to their Cisf,u. These results indicate that the unbound concentrations of the fluoroquinolones in the tissue interstitial fluids were the same as those in the venous plasma. The disk insertion technique seems to be useful for evaluating drug concentrations in tissue interstitial fluid.     

Early diagnosis of parenchymal lung diseases is now possible. Reduced risk of fibrosis and irreversibly reduced lung function]

Although parenchymal, or interstitial lung diseases constitute a heterogeneous category, a common feature is the occurrence of an alveolar and interstitial inflammatory reaction. The alveolitis may regress, but may also heal with scarring and fibrosis, resulting in chronic impairment of lung function. Early diagnosis is important in order to identify patients at risk of lung function impairment. Diagnosis has been facilitated by the advent of sophisticated, particularly radiological and bronchoscopic methods in recent years, thus enabling intervention at an earlier stage in the disease course. The various diagnostic alternatives available for the investigation of parenchymal lung diseases are reviewed in the article.     

Free pentosidine and neopterin as markers of progression rate in diabetic nephropathy. Collaborative Study Group

Stimulus-induced release of polyunsaturated fatty acids from membranes has been proposed to couple the processes of stimulus perception and oxylipin synthesis in the octadecanoid signaling pathway. This study investigated wound-induced changes in free fatty acids, diacylglycerol, and phospholipids at the site of wounding and at an unwounded area of the same wounded leaf in castor bean (Ricinus communis L.). Increases in free fatty acids and diacylglycerol and decreases in phospholipids were relatively large and continuous at the site of wounding. The changes at the unwounded area were selective and transient, suggesting a regulated activation of lipid turnover in response to wounding. In unwounded cells, the free fatty acids that increased in the early phase of wounding were linolenate and linoleate, which peaked within 5 min after wounding. Diacylglycerols that increased in unwounded cells were the species containing linolenate and linoleate, not those with oleate and stearate. Within 5 min of wounding, the levels of phosphatidylcholine and phosphatidylglycerol, but not other phospholipids, decreased in unwounded cells. These results provide evidence for the wound-induced selective increase in linolenate and linoleate in unwounded cells. The varied susceptibility of different phospholipids to hydrolysis after wounding indicates that phosphatidylcholine and phosphatidylglycerol may serve as substrates that lead to the increase in linolenate and linoleate in the early phase of wound response. The pattern of increases in polyunsaturated fatty acids, diacylglycerol, and phosphatidic acid and of decreases in phospholipids suggests the activation of a PLD-initiated signaling pathway in response to wounding in castor bean.     

Polyunsaturated fatty acids in serum lipids of reindeer during the close postnatal period

We examined serum fatty acid composition in reindeer during the close postnatal period (from < 8 h to 3 weeks) by using maternal serum as a reference point and focusing on the proportions of polyunsaturated fatty acids (PUFAs) in serum lipids. A striking dissimilarity was found in the serum PUFAs between the neonatals and their mothers. In particular, the proportions of linoleic acid (18:2) and alpha-linolenic acid in serum cholesteryl esters and phospholipids of the newborn reindeer were significantly lower than those of the mothers. Furthermore, serum phospholipids of the newborns had lower arachidonic acid and docosapentaenoic acid but higher docosahexaenoic acid proportions than the maternal phospholipids. Although the proportions of the principal C18 PUFAs were low in reindeer milk, they increased sharply in serum cholesteryl esters and phospholipids of the calves during the first few days after birth. In particular, there were significant positive correlations in the proportions of 18:2 between serum and milk lipids. We conclude that the proportions of the serum C18 PUFAs are low in the newborn reindeer, but they are increased during the close perinatal period by a rate which suggests an efficient mechanism for selective retention of these fatty acids from milk lipids.     

Gunshot injuries in infants and children in KwaZulu-Natal--an emerging epidemic?

AIM: To report the quantitation of the lipid composition of a corneal button from a Japanese woman in her 60s with clinically and histopathologically proved Schnyder's corneal dystrophy. METHODS: Total lipids extracted from the corneal button of the patient were analysed by the method of thin layer chromatography flame ionisation detection. Two different solvent systems were used for neutral lipid analysis and phospholipid analysis. Results were compared with three age matched corneal buttons obtained from cadaveric eyes. RESULTS: The lipids that accumulated in the cornea in Schnyder's dystrophy consisted mainly of unesterified cholesterol and phospholipids. The analysis of phospholipids showed sphingomyelin to be the predominant phospholipid in the patient's cornea. CONCLUSION: Findings suggest that this disorder involves a disturbance of the metabolism of cholesterol and/or sphingomyelin metabolism that is limited to the cornea.     

Regulatory mechanisms in maintenance and modulation of transmembrane lipid asymmetry: pathophysiological implications

The two leaflets of the plasma membrane of eukaryotic cells differ in lipid composition: the outer leaflet comprises mainly neutral choline containing phospholipids, whereas the aminophospholipids reside almost exclusively in the cytoplasmic leaflet. The importance of transmembrane lipid asymmetry may be judged from the fact that the cell invests energy to maintain this situation for which at least two regulatory mechanisms are held responsible. A translocase, selective for aminophospholipids, acts as an ATP-dependent pump for rapid inward movement of phosphatidylserine (PS) and phosphatidylethanolamine; in addition, a non-selective, but also ATP-dependent pump causes outward movement of phospholipids, be it at a much lower rate compared to the inward transport by the aminophospholipid translocase. These two systems, acting in concert, are thought to be the main players in the maintenance of a dynamic equilibrium of the phospholipids over both membrane leaflets. Dissipation of membrane lipid asymmetry can be elicited in different cell types under a variety of conditions; in particular, platelets upon activation rapidly lose their normal plasma membrane lipid distribution, but also in other blood cells, lipid asymmetry can be lost, be it at a much lower rate and extent than in platelets. A putative protein, referred to as "scramblase' has been described, which requires the continuous presence of elevated intracellular Ca(2+)-levels, to allow a rapid, non-selective and bidirectional transbilayer movement of phospholipids. Although scrambling of lipids does not require ATP as such, preliminary studies suggest the possible involvement of one or more phosphorylated proteins. The most prominent consequence of the loss of phospholipid asymmetry is exposure of PS in the outer leaflet of the plasma membrane. Surface-exposed PS serves several important physiological functions: it promotes assembly of enzyme complexes of the coagulation cascade, it forms a signal for cell-cell recognition, which is important for cell scavenging processes. Surface-exposure of PS is an early phenomenon of apoptosis and appears to be involved in efficient removal of these cells. In addition, PS in the outer leaflet of cells is thought to play a role in cell fusion processes. It may be clear from the foregoing, that the amount of PS present at the cell surface needs to be tightly controlled, and that an impairment of this process leads to either excessive- or diminished exposition of PS which may have several pathophysiological consequences.