Pharmacological study of oyster mushroom (Pleurotus ostreatus) extract on isolated guinea pig trachea smooth muscle.

Mushroom farm workers suffer from respiratory symptoms during the farming of mushrooms. The objective of this study was to analyze the effects of oyster mushroom (Pleurotus ostreatus) extract (OME) on isolated guinea pig tracheal smooth muscle in vitro. Isolated guinea pig tracheal tissue from 27 nonsensitized guinea pigs were studied. The OME was obtained from indoor mushroom growing fields and prepared as a 1:10 w/v aqueous solution. Dose-related contractions of nonsensitized guinea pig trachea were demonstrated using these extracts. The OME contained significant quantities of bacterial components (eg., endotoxin: 43,072.92 EU/mg). Parallel, pharmacological studies were performed by pre-treating the tissues with mediator-modifying agents including atropine, indomethacin, pyrilamine, BPB, acivicin, NDGA, captopril, TMB8 and capsaicin. Atropine consistently and strikingly reduced the contractile effects of this extract. These observations suggest an interaction of the OME with parasympathetic nerves or more directly with muscarinic receptors. Pretreatment with TMB8 (inhibitor of intracellular calcium mobilization) also significantly blocked the constrictor effect of OME, indicating a role of calcium mobilization in the constricting effect of OME. Inhibition of contraction by blocking of other mediators was less effective and varied depending on the drug. We conclude that OME causes a dose-related airway smooth muscle constriction by nonimmunological mechanisms involving a variety of airway mediators and possibly cholinergic receptors. This effect is not dependent on pre-sensitization of the guinea pigs.

Pharmacologic properties of brewery dust extracts in vitro.

STUDY OBJECTIVES: To study the effects of extracts of brewery dust on isolated guinea pig tracheal smooth muscle in vitro. DESIGN: Parallel pharmacologic intervention on guinea pig tracheal rings that were obtained from the same animal. SETTING: Mount Sinai School of Medicine, Department of Pulmonary Medicine. MATERIAL: The isolated guinea pig tracheal tissue of 18 guinea pigs. INTERVENTIONS: Pretreatment of guinea pig rings by mediator-modifying agents before challenge with the brewery dust extracts. MEASUREMENTS AND RESULTS: The effect of brewery dust extracts on isolated guinea pig tracheal smooth muscle was studied using water-soluble extracts of dust obtained from brewery materials, including hops, barley, and brewery yeast. Dust extracts were prepared as a 1:10 (wt/vol) aqueous solution. Dose-related contractions of nonsensitized guinea pig tracheas were demonstrated using these extracts. The dust extracts contained significant quantities of bacterial components (eg, endotoxin and n-formyl-methionyl-leucyl-phenylalanine), but these agents were not thought to contribute directly to the constrictor effect of the dusts. Pharmacologic studies were performed by pretreating guinea pig tracheal tissue with the following drugs known to modulate smooth muscle contraction: atropine; indomethacin; pyrilamine; LY171883; nordihydroguaiaretic acid; captopril; thiorphan; verapamil; and TMB8. The constrictor effects of the dust extracts were inhibited by a wide variety of agents, the patterns of which depended on the dust extract. Atropine consistently and strikingly reduced the contractile effects of these extracts. These observations may suggest an interaction of the extracts with parasympathetic nerves or, more directly, with muscarinic receptors. The inhibition of contraction by the blocking of other mediators was less effective and varied with the dust extract. CONCLUSIONS: We suggest that brewery dust extracts cause a dose-related airway smooth muscle constriction by nonimmunologic mechanisms involving a variety of airway mediators and, possibly, cholinergic receptors. This effect is not dependent on presensitization of the guinea pigs.

Acute inflammatory reaction in rats after intratracheal instillation of material collected from a nylon flocking plant.

Several cases of interstitial lung disease have been diagnosed among workers at a nylon flock plant, but the etiologic agent for the disease outbreak was unknown. The results of a medical survey and industrial hygiene study indicated that the dust present in the plant may be responsible. Thus, airborne dust collected at the plant was examined for its inflammatory potential in rat lungs. The endpoints measured were: (1) breathing rates, (2) differential cell counts of bronchoalveolar lavage cells, (3) alveolar macrophage (AM) chemiluminescence, (4) albumin concentration and matrix metalloprotease activities in the acellular fluid from the initial bronchoalveolar lavage, and (5) pulmonary histopathology. In the first study, rats received a single dose of the airborne dust sample (10 mg/kg body weight) by intratracheal (IT) instillation. At 1 d post-IT, all inflammatory endpoints were significantly increased versus controls, but by 29 d post-IT they did not differ significantly from controls. Histopathology demonstrated mild to moderate, multifocal, suppurative pneumonia, usually centered around bronchioles, at 1 d post-IT. At 29 d post-IT, pulmonary inflammation was minimal to mild and characterized by alveolar histocytosis usually restricted to the immediate area of retained bire-fringent fibers. In subsequent experiments, airborne dust was extracted with water and the dust (washed airborne dust) and water extract (soluble fraction) were separated by centrifugation for further study. Nylon tow dust was prepared in the laboratory by milling uncut nylon strands (called tow) that had not been treated with the finish or dyes that are commonly used in the flock plants. Rats were administered a single dose of a dust sample (10 mg/kg body weight) or the soluble fraction (1.3 ml/kg body weight) by IT administration and the same endpoints were measured at 1 d post-IT. The dust samples caused significant increases in all of the inflammatory endpoints; however, the soluble fraction was much less active. Histological analysis of the lungs 1 d post-IT confirmed lung inflammation was occurring and tended to center around bronchioles. The results suggest that: (1) nylon flocking generates particles of respirable size that can interact with AM in the lung and can be detected in the lung 29 d after exposure, (2) the dust samples examined cause an inflammatory response, (3) water-extractable agent(s) from airborne dust contribute only minimally to the inflammatory response, and (4) the acute inflammatory response to these dusts is substantial when compared to other pathologic occupational dusts previously examined in our laboratory.

Effects of recycled paper dust extracts on isolated guinea pig trachea.

The effect of paper dust collected at two different locations in a paper recycling plant (PD1 and PD2) on isolated nonsensitized guinea pig tracheal smooth muscle was studied in vitro. Dust extracts were prepared as a 1:10 w/v aqueous solution. Dose-related contractions of guinea pig tracheal rings were elicited with both PD1 and PD2. Pharmacologic studies were performed with atropine (10(-6) M), indometacin (10(-6) M), pyrilamine (10(-6) M), LY171883 (10(-5) M), nordihydroguaiaretic acid (10(-5) M), and TMB8 (10(-5) M). The possible role of endogenous neuropeptides in this constrictor process was studied by depleting neural mediators with capsaicin (5 x 10(-6) M) before challenge with dust extracts. Constrictor effects were partially inhibited by a wide variety of the mediator blocking agents. The effects of both extracts were almost totally inhibited by the anticholinergic agent atropine, suggesting that a principal pathway mediating this response may involve the parasympathetic nervous system. The intracellular calcium-blocking agent TMB8 also induced a reduction of the contractile responses to PD1 and PD2 consistent with the well established role of intracellular calcium in smooth muscle constriction. Pretreatment with capsaicin significantly increased the contractile activity of paper dust extracts but only at the higher doses of these extracts. This suggests that the effect of paper dust is not initiated by the release of mediators stored in sensory nerves but that the prerelease of these mediators may enhance the constrictor effects of these dusts. We suggest that paper dust extracts cause dose-related airway smooth muscle constriction possibly associated with the release of cholinergic as well as other mediators. The constrictor effect does not require tissue presensitization or the release of neuropeptides from sensory nerves.

Home care of the patient who has pregnancy-induced hypertension.

The home health population is more seriously ill now than in the past. Patients with an illness previously treated in the hospital are being cared for in the home. Pregnancy-induced hypertension is one such process that is being treated by home care nurses. The purpose of this article is to assist the home healthcare nurse in the assessment and management of the patient who has pregnancy-induced hypertension.

Polyadenylation of mRNA: minimal substrates and a requirement for the 2' hydroxyl of the U in AAUAAA.

mRNA-specific polyadenylation can be assayed in vitro by using synthetic RNAs that end at or near the natural cleavage site. This reaction requires the highly conserved sequence AAUAAA. At least two distinct nuclear components, an AAUAAA specificity factor and poly(A) polymerase, are required to catalyze the reaction. In this study, we identified structural features of the RNA substrate that are critical for mRNA-specific polyadenylation. We found that a substrate that contained only 11 nucleotides, of which the first six were AAUAAA, underwent AAUAAA-specific polyadenylation. This is the shortest substrate we have used that supports polyadenylation: removal of a single nucleotide from either end of this RNA abolished the reaction. Although AAUAAA appeared to be the only strict sequence requirement for polyadenylation, the number of nucleotides between AAUAAA and the 3' end was critical. Substrates with seven or fewer nucleotides beyond AAUAAA received poly(A) with decreased efficiency yet still bound efficiently to specificity factor. We infer that on these shortened substrates, poly(A) polymerase cannot simultaneously contact the specificity factor bound to AAUAAA and the 3' end of the RNA. By incorporating 2'-deoxyuridine into the U of AAUAAA, we demonstrated that the 2' hydroxyl of the U in AAUAAA was required for the binding of specificity factor to the substrate and hence for poly(A) addition. This finding may indicate that at least one of the factors involved in the interaction with AAUAAA is a protein.

Development of improved defined media for Clostridium botulinum serotypes A, B, and E.

The minimal nutritional growth requirements were determined for strains Okra B and Iwanai E, which are representatives of groups I and II, respectively, of Clostridium botulinum. These type B and E strains differed considerably in their nutrient requirements. The organic growth factors required in high concentrations by the Okra B strain (group I) were arginine and phenylalanine. Low concentrations (less than or equal to 0.1 g/liter) of eight amino acids (methionine, leucine, valine, isoleucine, glycine, histidine, tryptophan, and tyrosine) and of five vitamins (pyridoxamine, p-aminobenzoic acid, biotin, nicotinic acid, and thiamine) were also essential for biosynthesis. The 10 required amino acids could be replaced by intact protein of known composition by virtue of the bacterium's ability to synthesize proteases. Glucose or other carbohydrates were not essential for Okra B, although they did stimulate growth. Quantitatively, the most essential nutrients for Okra B were arginine and phenylalanine. In contrast, the nonproteolytic strain, Iwanai E (group II), did not require either arginine or phenylalanine. It required glucose or another carbohydrate energy source for growth and did not utilize arginine or intact protein as a substitute source of energy. Iwanai E utilized ammonia as a nitrogen source, although growth was stimulated significantly by organic nitrogenous nutrients, especially glutamate and asparagine. Iwanai E also required biosynthesis levels of seven amino acids (histidine, isoleucine, leucine, tryptophan, tyrosine, valine, and serine), adenine, and six vitamins (biotin, thiamine, pyridoxamine, folic acid, choline, and nicotinamide). Calcium pantothenate also stimulated growth. On the basis of the nutritional requirements, chemically defined minimal media have been constructed for C. botulinum serotypes A, B, E, and F (proteolytic).(ABSTRACT TRUNCATED AT 250 WORDS)

Comparison of fracture strength of porcelain-veneered-to-high noble and base metal alloys.

Sixty crowns were cast from a commercial high noble and base metal alloy. The porcelain applied to the crowns was fired 10 times and fractured under gradual application of load. The fracture strength of the porcelain-veneered-to-base metal and high noble alloys subjected to repeated firings was compared. The results were: The fracture strength of porcelain-veneered-to-high noble alloys remained relatively constant for five firings but decreased significantly as the firings increased to 10. Ten firings did not significantly affect the fracture strength of porcelain-veneered-to-base metal alloys. Porcelain-veneered-to-base metal alloy crowns had a higher fracture strength compared with high noble alloy crowns.

Effects of mechanical activity and hormones on myocardial glucose and fatty acid utilization.

The effects of increased cardiac work on glycolysis, the citric acid cycle, and oxidation of fatty acids were studied in isolated rat hearts. Glycolysis was stimulated by increased work in heart perfused with glucose alone or with glucose, high levels of insulin, and low levels of palmitate. With glucose alone, stimulation was associated with a rapid decrease in phosphate potential and rapid activation of phosphofructokinase, but an apparently slower activation of glucose transport. With glucose, insulin, and palmitate present, stimulation of glucose utilization was rapid and correlated with activation of phosphofructokinase.