Injurious Substance Research Articles

Registering Cosmetics? The Constitution of Legal Form and Injurious Substance in Canada (1945-1946).

In midcentury Canada, legislative drafters, government lawyers, food and drug officials, and ministers grappled with cosmetics. Faced with constitutional concerns about cosmetic licensing, these actors drafted legislative amendments that would instead require cosmetics to be registered. In contrast to people or land, the registration of products, substances, or things has received little attention in sociolegal scholarship. Building on work investigating law's temporalities and materiality, this account traces how in-formed by the constitutional doctrine that apprehended substances through the legal form of prohibition, cosmetics were rendered in draft legislation as constituted of ingredients that may cause injury. Injury, in this account, is a material-temporal regime. Yet cosmetic injury was neither static nor singular, as it was catalysed differently by distinctive regulatory devices. This is shown by last-minute changes to the bill which retooled cosmetic registration, from an information extraction device for anticipating future harms, into a recording device for capturing latent harms.

Gastro Esophageal Reflux Disease

Gastro esophageal reflux disease is also known as GERD. It is a long term condition where stomach contents come back up into the esophagus. Resulting in either symptoms or complications. Symptoms include the taste of acid in the back of the mouth, heartburn, bad breath, chest pain, vomiting, breathing problems and wearing away of the teeth complications includes oesophagitis, esophageal strictures and Barrett’s esophagus. Recent studies have demonstrated that peripheral and central factors are pivotal for the emergence of symptoms after gastroesphageal reflux had occurs supporting the view the GERD is a sensory -motor disorder rather than motor disorder alone. The primary pathophysiologic event in GERD is the movement of acid, pepsin and other injurious substance from the stomach in to the esophagus. GERD is a common problem world-wide, the frequency and severity of GERD and severity of GERD and its complications such as burette’s esophagus and geographic variations. most studies from India suggests that these might be less in the Indian population on the other hand studies in a multiethnic population showed that people of Indian origin are at higher risk of GERD than ethnic Malay of Chinese.

Cryopreservation of Chlamydomonas reinhardtii: A cause of low viability at high cell density

Cryopreservation is a practical method for stabilizing the genetic content of living algae over long periods of time. Yet, Chlamydomonas reinhardtii, the algal species most often utilized in studies requiring genetically defined strains, is difficult to cryopreserve with a consistently high post-thaw viability. Work described here demonstrates that C. reinhardtii retains high viability only when cryopreserved at a low cell density. Low viability at high cell density was caused by the release of an injurious substance into the culture medium. Rapid freezing and thawing under non-cryoprotective conditions released large amounts of the injurious substance. Heat denaturation of cells prevented the release of the injurious substance, but heating did not inactivate it after it was released. Even when concentrated, the injurious substance was non-toxic to cells under normal culture conditions. Reduced viability of cells cryopreserved in the presence of the injurious substance could not be attributed to changes in the tonicity of the medium. A mutant strain of C. reinhardtii (cw10) with a greatly diminished cell wall did not release a substance that reduced the post-thaw viability of wild-type or cw10 cryopreserved cells. Cryopreservation of cw10 cells was achieved with approximately the same post-thaw viability irrespective to the cell concentration at the time of freezing. Acid treatment of the injurious substance was able to partially diminish its injurious effect on cells during cryopreservation. We propose that diminished viability of C. reinhardtii cells cryopreserved at high cell densities is caused by the enzymatic release of a cell-wall component.

Airway epithelial cells: functional roles in airway disease.

"Airway Epithelial Cells: Functional Roles in Airway Disease." American Journal of Respiratory and Critical Care Medicine, 150(5_pt_2), pp. S27–S30

Mucosal adaptation to aspirin induced gastric damage in humans. Studies on blood flow, gastric mucosal growth, and neutrophil activation.

The gastropathy associated with the ingestion of non-steroidal anti-inflammatory drugs (NSAIDs) such as aspirin is a common side effect of this class of drugs, but the precise mechanisms by which they cause mucosal damage have not been fully explained. During continued use of an injurious substance, such as aspirin, the extent of gastric mucosal damage decreases and this phenomenon is named gastric adaptation. To assess the extent of mucosal damage by aspirin and subsequent adaptation the effects of 14 days of continuous, oral administration of aspirin (2 g per day) to eight healthy male volunteers was studied. To estimate the rate of mucosal damage, gastroscopy was performed before (day 0) and at days 3, 7, 14 of aspirin treatment. Gastric microbleeding and gastric mucosal blood flow were measured using laser Doppler flowmeter and mucosal biopsy specimens were taken for the estimation of tissue DNA synthesis and RNA and DNA concentration. In addition, the activation of neutrophils in peripheral blood was assessed by measuring their ability to associate with platelets. Aspirin induced acute damage mainly in gastric corpus, reaching at day 3 about 3.5 on the endoscopic Lanza score but lessened to about 1.5 at day 14 pointing to the occurrence of gastric adaptation. Mucosal blood flow increased at day 3 by about 50% in the gastric corpus and by 88% in the antrum. The in vitro DNA synthesis and RNA concentration, an index of mucosal growth, were reduced at day 3 but then increased to reach about 150% of initial value at the end of aspirin treatment. It is concluded that the treatment with aspirin in humans induces gastric adaptation to this agent, which entails the increase in mucosal blood flow, the rise in neutrophil activation, and the enhancement in mucosal growth.

Adsorbed HNO 2/NO redox couple at Pt(111) single-crystal electrode

Nitrogen oxide (NOx), produced mainly in the exhaust gases of automobile engines and factory turbines, is known as an injurious substance to the human respiratory organs and nervous system. It is also an important source of acid rain. Nitric oxide has been the subject of intense attention in the last 5 years because of its important biological role in the body which had not been recognized previously [1]. The adsorption and decomposition mechanisms of NO x on a well-defined single-crystal catalyst surface have been studied extensively in the gas phase using a variety of methods, such as low energy electron diffraction (LEED), Auger electron spectroscopy, IR absorption spectroscopy, X-ray photoelectron spectroscopy (XPS) etc., and these results have been well reviewed [2-4]. Electrochemical investigations of NOx have been carried out by many groups, mainly on polycrystalline Pt electrodes. The electrochemical behaviour appears to be more complicated than that observed in gas + solid catalysis. Schmid and Neumann [5] investigated the equilibrium potential of the HNO2/NO redox system in solution and obtained E ° = 0.983 V. Many groups have concluded from the kinetic analysis of cyclic voltammograms obtained in acid solution that the formation of NO is the first reduction step of HNO2 [6-9]. Clavilier and Chauvineau [10] have reported that a (poly)platinum surface was covered by NO during cleaning with an argon glow discharge. The NO was removed irreversibly at 0.45V/SCE in a positive potential scan. Gadde and Bruckenstein [11] carried out bulk electrolysis of nitrite in 0.1 M HCIO4 at a Pt electrode. Their product analysis showed only NO above 0.5V/RHE. Nishimura et al. [12] examined the electroreduction product of nitrite and nitrate ions at a porous Pt electrode in H2SO 4 using the differential electrochemical mass spectroscopy (DEMS) method. NO has been detected in the potential region 0.6-1.0 V/RHE.

Gastric adaptation to nonsteroidal anti-inflammatory drugs in man.

Adaptation describes the phenomenon in which visible gastric mucosal injury lessens or resolves completely despite continued administration of an injurious substance such as aspirin. Adaptation occurs in man although the mechanism remains unclear. Recent evidence suggests increased cell proliferation and correction of nonsteroidal anti-inflammatory drug induced reduction in gastric blood flow as possibly being important. Gastric erosions and ulcers in chronic nonsteroidal anti-inflammatory drug users represent failed adaptation. Gastric erosions and ulcers in chronic nonsteroidal anti-inflammatory drug users represent failed adaptation. The factors responsible for failure of adaptation are unknown but one clue is that there appears to be a dose-response effect relating anti-inflammatory dose and effectiveness of adaptation (i.e., adaptation is delayed, or less effective, when higher anti-inflammatory doses are administered). Gastric adaptation can be enhanced by co-therapy with synthetic prostaglandins but not with sucralfate or H2-receptor antagonists.

Extrafloral Nectar: Entomological Implications

Linnacus created the word “nectary” (nectarium) in 1735 to denote specialized epidermal glands composed of small, thin-walled secretory cells from which nectar is brought to the surface through modified stomata (Fahn 1979). Nectar was defined aptly by Trelease (1879) as “a fluid always sapid, usually sweet, often odorous, which is elaborated in any part of a plant, remaining where formed or making its way to some other part; its raison d'etre being the necessity for the removal of some useless or injurious substance, or for some provision to attract nectar-loving animals to the plant for some definite purpose.” The distinction between floral (nuptial) nectaries and extrafloral (vegetative) nectaries was made by Caspary in 1848 (Fahn 1979). The mutual role of floral nectar in plant pollination and insect nutrition is well known (McGregor 1976). Although extrafloral nectar has been the subject of naturalists' curiosity and hypotheses for more than a century (Bentley 1976), only in recent years have we begun to understand its source, characteristics, functions, and chemical ecology.

EFFECTS OF ENVIRONMENTAL FACTORS ON OXIDIZING ENZYMES OF ROSE MALLOW SEEDS

The power of plant tissues to break up hydrogen peroxide into water and molecular oxygen was known long before catalase was recognized as an enzyme, discovered, and named by Loew (18) in 1901. This discovery opened a new field for investigation and many studies were undertaken. The wide distribution of catalase in plant and animal tissue led Loew to conclude that it might serve as a protective measure against the injurious protoplasmic effects of hydrogen peroxide and possibly other related compounds formed in respiration. Dixon (8) has shown that when purine bases are oxidized by molecular oxygen in the presence of xanthine-oxidase as a catalyst, the oxidase undergoes destruction during the course of the reaction owing to the hydrogen peroxide that is formed. He found that this destruction could be prevented by the addition of catalase. Pneumococci in contact with a free supply of oxygen produced hydrogen peroxide in sufficient amount to inhibit their growth, but if catalase were added the bacteria grew vigorously. A close correlation between catalase activity and respiration was found in potatoes (2), in rice grains germinated under water (22), and in sweet corn (3). Crocker and Harrington (6) found this same correlation in the seeds of Johnson grass but not in Amaranthus. Rhine (26) using a number of different seeds concluded that catalase activity is a measure of the metabolic activity only when there is a rapid change in respiration. The absence of catalase activity in certain blue green algae (14) and in anaerobic bacteria (20) indicates that catalase is not essential to the respiration of all cells. McLeod and Gordon (20) consider it possible that catalase destroys some injurious substance such as H202 which is produced by aerobic organisms and by anaerobic organisms in the presence of oxygen ; thus anaerobic organisms lacking catalase would be injured when exposed to oxygen. A variation in catalase activity was observed by Pope (24, 25) in the different parts of the same barley plant. The relation of the catalase activity to physiological breakdown in Jonathan apples convinced Neller (23) that catalase activity could be used as a true index of the rate of metabolic activity. Heinicke (15,16) concluded that catalase activity is a highly sensitive index to changes in the internal condition of the apple tree, and that this activity varies with the season, with the part of the tree tested, and with

The local treatment of wounds

B Y the “Local Treatment of Wounds” is meant treatment as apphed directIy to tissues, the continuity of which has been severed. Genera1 treatment such as the administration of bIood, fluids, chIorides, foods, vaccines and antitoxins wiI1 not be discussed. The influence of disease states such as anemia and diabetes wiI1 purposeIy be omitted. Even with these limitations the subject is Iarge and must necessariIy be confined to the principIes of treatment without reference to specific Iocations of wounds. SpeciaI considerations enter into the treatment of wounds of the eye, brain, pIeura, heart, peritoneum, urinary bIadder, joints and other important structures which makes of each one a subject in itseIf. The principIes underIying the treatment of wounds are the same, however, regardIess of their extent or Iocation. Before studying the treatment of wounds it is proper to inquire into their methods of heaIing. How do wounds heaI? What agencies or factors faciIitate this process and which ones retard it? Most pathoIogists and surgeons speak of wounds as heaIing by first and second intention. The two processes are essentiaIIy the same. By first intention is meant the prompt heaIing of a wound with very IittIe inffammatory reaction, the reaction being so smaI1 that there is no redness and no grossIy appreciabIe sweIIing of the wound and no secretion from it other than cIear serum or norma bIood within the first few hours. HeaIing by second intention is the same process to which is added the phenomena of inflammation. Inffammation is due to some injury to the tissues and causes a deIay in the heaIing process. The amount of deIay depends upon the severity of the injury and the abihty of the body to overcome it.‘Once the irritant is removed by the inffammatory process heaIing rapidIy progresses. Since heaIing is due to an actua1 growth of ceIIs anything which prevents the approximation of tissues during the heaIing process and disturbs that process once it is started wiI1 deIay heaIing. To obtain prompt heaIing, or in other words heaIing by first intention, we must excIude from wounds any factor which prevents approximation and any injurious substance. Substances injurious to wounds may be divided into bacteriaI, mechanica1, physica1, and chemica1. The importance of excIuding bacteria from wounds is now generaIIy recognized and the various methods of excIusion wiI1 not be described. Attention is caIIed however to the recent work of Dandy and of MeIeney. Dandy emphasized the importance of adequate steriIizations of suppIies. He has proved that a constant minimum pressure of 20 pounds for at Ieast one hour is necessary to kiI1 bacteria by autocIaving. MeIeney found that members of the operating room personne1 sometimes carried streptococci in their noses and throats which Iead to serious postoperative infections. He reduced the incidence of such infections by covering the nose and mouth of every person entering the operating room. RoutineIy now when postoperative infections occur he makes cuItures of the noses and throats of the entire surgica1 staff to discover if carriers are present.

INFLAMMATION

Although most pathologists are agreed as to the general character of inflammation, various definitions of this fundamental pathologic process have been offered. Some define inflammation merely as the reaction of tissues to injury. Others, following the lead of Cohnheim, define it as the reaction affecting specifically the wall of blood vessels after injury, i. e., the increased permeability that allows the escape of plasma and blood corpuscles into the surrounding tissue. By some, notably Cohnheim¹and Adami,²inflammation is viewed as a process adapted to reduce the harmful consequences of an injury; Metchnikoff, Marchand, and Councilman regarded it solely as a reaction excited by the presence of something injurious to the tissue. Opie³defined it as a process by means of which cells and serum accumulate about an injurious substance and tend to remove or destroy it. In the course of this presentation, an attempt will be

ON THE RELATION OF TETANY TO THE PARATHYROID GLANDS AND TO CALCIUM METABOLISM

ON THE RELATION OF TETANY TO THE PARATHYROID GLANDS AND TO CALCIUM METABOLISM

Effect of Certain Solids upon the Growth of Seedlings in Water Cultures

(WITH FOUR FIGURES) IN certain investigations on the growth of wheat seedlings in aqueous extracts of soil, it was observed that the growth of these plants was greatly accelerated by the presence in the medium of undissolved calcium carbonate. That the observed acceleration was not due to an increase in dissolved calcium was apparent from the fact that the presence of other slightly soluble salts of this element failed to produce any response. It appeared possible that the effect of calcium carbonate might be due to its taking up some injurious substance present in the extract. This was suggested by NXGELI'S well-known discovery2 that water, which is toxic to algae because of minute traces of metals, can be improved by placing in it such insoluble bodies as graphite, paraffin shavings, or torn filter paper. It was determined to try other slightly soluble compounds which might remove from solution small amounts of solutes, either by chemical action or mechanically. The results of this investigation make up the present paper. The Russian variety of wheat known as Chul, obtained from Arizona, was used in most of these experiments. The seedlings were germinated in sand and then grown in water cultures in large-mouthed black bottles of about 60cc capacity. They were fixed in cork stoppers, four in a bottle, in the manner described by WHITNEY and CAMERON3 for cultures of this kind, so that the roots were submerged in the solution while the seeds were just above its surface. The solutions were always aerated by violent and repeated shaking before the cultures were started. During the growth of the plants the bottles were weighed in groups of three at intervals of three or four days, and the water lost was replaced with distilled water. The manner