ELECTRON-OPAQUE BODIES AND FAT DROPLETS IN MOUSE LIVER AFTER FASTING OR GLUCOSE INJECTION

Fasting produces an increased mobilization of lipid from adipose tissue to the liver and a decreased hepatic lipogenesis, but the administration of glucose stimulates lipid synthesis by the liver. After fasting of C3H mice numerous electron-opaque bodies and large lipid droplets were present in the liver. In the liver of untreated controls only a few small electron-opaque bodies and an occasional fat droplet were observed. After glucose injection the number of electron-opaque bodies in the liver was no greater than that observed in livers of saline-injected controls. In the livers of all groups these bodies were located intracellularly within cytoplasmic vesicles; those in extracellular locations were not membrane bounded and were located at indented and thickened hepatocyte plasma membranes or within the space of Disse. In fasted liver the dense bodies were often associated with large fat droplets.     

Derepression of Phosphomannose Isomerase by Regulator Gene Mutations Involved in Capsular Polysaccharide Synthesis in Escherichia coli K-12

A regulator gene mutation (capR) that causes increased synthesis of capsular polysaccharide and derepressed synthesis of several enzymes involved in polysaccharide synthesis also derepresses phosphomannose isomerase (PMI) synthesis. In contrast, a second mutation (capS, which maps separately from capR) that causes increased production of the same polysaccharide does not lead to increased synthesis of PMI (nor of several of the other enzymes involved in polysaccharide synthesis). Introduction of the capR9 allele by transduction or mutation of capR(+) to capR can change the phenotype of a mannose-negative nonmucoid strain to a mannose-positive mucoid phenotype. Thus, genotype capR(+)man-2 is mannose-negative and nonmucoid, but genotype capR9 man-2 is mannose positive and mucoid. Other interactions between these alleles in the synthesis of capsular polysaccharide are recorded.     

Psychological Implications of Cystic Fibrosis

A psychological and psychiatric study of 11 children with cystic fibrosis revealed major psychological problems in all of them. Among the parents of the majority of these children, marked psychopathology and gross marital discord were noted. Popular literature concerning cystic fibrosis had a negative effect on the child''s attitude toward the disease. Virtually all of these patients showed a preoccupation with death. In this study, the necessity of psychiatric consultation as an integral part of current intensive treatment programs in cystic fibrosis clinics was demonstrated.     

Respiratory epithelial permeability after cigarette smoke exposure in guinea pigs

The purpose of this study was to determine the pathology of cigarette smoke-increased permeability at the bronchioalveolar junction of the guinea pig. After exposure to either smoke or room air, guinea pigs were anesthetized and fluorescein isothiocyanate-dextran (FITC-D, mol wt 10,000) was aerosolized into their lungs. Blood samples taken through a carotid arterial cannula were analyzed by gel chromatography and spectrofluorometry for the presence of FITC-D. The results confirmed that, after smoke exposure, increased amounts of intact FITC-D molecules with a reported Einstein-Stokes radius of 22.2 A crossed the respiratory epithelium into the vascular space. Transmission electron-microscopic studies showed that the FITC-D diffused across damaged type I pneumocyte membranes and cytoplasm to reach the basal lamina and entered the alveolar capillaries through endothelial tight junctions. Damage to the alveolar epithelium was more frequent for the smoke-exposed animals than the room air-exposed animals (P less than 0.05). We conclude that smoke exposure damages type I cells and that inhaled FITC-D crosses the epithelial barrier at damaged type I cells of the bronchioloalveolar junctions.     

Plant regeneration from hypocotyl and petiole callus of Trifolium pratense L.

Red clover (Trifolium pratense L.) seedlings were screened for the ability to regenerate plantlets from hypocotyl-derived callus tissue. Media sequences described by Beach and Smith (1979) and Collins and Phillips (1982) and a variation using media from both sequences were tested. Plantlets were regenerated from three out of 642 genotypes. In all three cases, callus was initiated on B5C medium and regeneration was accomplished on SPL medium. Attempts to regenerate plants from petiole-derived callus tissue have so far been successful only with regenerants of clone F49. Petiole callus from epicotyl-derived F49 plants proved to be non-regenerative. Pollen viability varied significantly among individuals regenerated from callus cultures of clone F49. Root tip squashes from F49 regenerants revealed the normal diploid chromosome number (2n=14). The frequency of regeneration within progeny from reciprocal crosses between F49 regenerants and several non-regenerative genotypes was 29%.Abbreviations 2,4-D 2,4-dichlorophenoxyacetic acid - BAP benzylaminopurine - KN kinetin - NAA -naphthaleneacetic acid     

Study of the in-vivo antioestrogenic action of N,N-diethyl-2-[4-(phenylmethyl)phenoxy]ethanamine HCl (DPPE), a novel intracellular histamine antagonist and antioestrogen binding site ligand

N,N-Diethyl-2-[4-(phenylmethyl)phenoxy]ethanamine HCl (DPPE) binds with high affinity to the antioestrogen binding site (AEBS), but not to the oestrogen receptor. There is an association of AEBS with a novel intracellular histamine receptor (H1C) of micromolar affinity through which histamine acts as a second messenger. An optimal dose of 4 mg DPPE/kg antagonized the uterine growth-stimulating effects of oestradiol in immature oophorectomized rats. Unlike tamoxifen, DPPE alone was not a partial agonist, but decreased uterine size and weight below control values at concentrations between 0.1 and 75 mg/kg. DPPE also antagonized oestradiol-stimulated uterine growth at 72 h; the inhibition observed was not significantly different from that seen with tamoxifen. Oestradiol-treated animals receiving the combination of DPPE (4 mg/kg) + low dose tamoxifen (0.04 mg/kg) for 72 h had significantly smaller uteri than did those receiving the same dose of DPPE or tamoxifen alone. Histologically, either DPPE or tamoxifen antagonized oestradiol stimulation of eosinophil migration and glandular epithelial proliferation; the latter inhibition was significantly greater for DPPE + tamoxifen (0.04 mg/kg) than for the same dose of DPPE or tamoxifen alone. Unlike tamoxifen, DPPE did not antagonize oestradiol stimulation of luminal epithelial proliferation, but in the presence of oestradiol, DPPE significantly decreased tamoxifen (0.65 mg/kg)-induced hypertrophy of the luminal epithelium. Based on these findings, we suggest that binding to the AEBS/intracellular histamine receptor is important to the action of antioestrogens.     

Growth versus molting time of caterpillars as a function of temperature,nutrient concentration and the phenolic rutin

Summary A factorial experiment tested the effects of varying nutrient concentration (normal versus diluted), presence or absence of the phenolic allelochemical rutin and daytime temperature (20, 25 and 30° C) on growth, molting and food utilization efficiencies of tobacco hornworms (Manduca sexta). Two of the utilization efficiencies (approximate digestibility and efficiency of conversion of ingested food) were unaffected by temperature; the third one, efficiency of conversion of digested food, was affected by temperature but there was no consistent effect. Lower temperatures significantly increased the proportion of the stadium spent molting, with larvae at a daytime temperature of 20° C spending 9% more of the stadium in molting than larvae at 30° C. Growth time was not influenced by nutrient concentration. When temperature was low and rutin absent, molt time and the proportion of the stadium spent molting were affected by nutrient concentration. Addition of the phenolic rutin did not have an appreciable effect on growth time or digestive processes. However, it increased molting time by 7 to 14% and thus increased the duration of the stadium and reduced relative growth rate. These results indicate that the effect of food quality on growth rate is a function of the thermal conditions of insect herbivores. At cooler temperatures, a disproportionate increase in time spent molting, rather than altered food utilization efficiencies, contributed to lower growth rates. The consequences for larval growth of fluctuating temperatures due to diurnal cycles and the presence of predators forcing larvae into thermally suboptimal microhabitats are discussed.