Regulation of fibronectin biosynthesis by glucocorticoids in human fibrosarcoma cells and normal fibroblasts

When treated with the synthetic glucocorticoid dexamethasone, HT1080 human fibrosarcoma cells show changes in morphology, adhesion, and the extracellular matrix. Dexamethasone treatment results in a tenfold increase in the rate of fibronectin biosynthesis in HT1080 cells and a twofold increase in untransformed, normal human fibroblasts. Maximal induction levels are attained within one cell generation, while decay of the response requires several cell cycles. Pulse-chase studies showed that most of the newly synthesized fibronectin is secreted into the medium. The glucocorticoid antagonist, RU-486, blocks the dexamethasone-induced changes but does not alter the basal rate of fibronectin production. Therefore, fibronectin biosynthesis appears to be controlled by two distinct mechanisms--one, regulating basal rates of fibronectin production, which is transformation-sensitive and glucocorticoid-independent; and another, which is mediated by the glucocorticoid receptor, resulting in elevated rates of fibronectin biosynthesis upon dexamethasone treatment both in normal fibroblasts and in HT1080 cells.     

Cytogenetics of ticks (Acari: Ixodoidea)

Chromosomes and sex determination of 9 species of Haemaphysalis assigned to 4 subgenera are described. H. (tAlloceraea) kitaokai possesses an XX∶XO sex chromosome system with 18 autosomes plus XX in females; 18 plus X in males. H. (Kaiseriana) hystricis has 18 +XX and 18 + XY in females and males, respectively, in most specimens, but a supernumerary chromosome is present in some individuals. A supernumerary chromosome was also observed in 1 male H. (Aborphysalis) formosensis. These two species are the second and third species of ticks reported to have supernumerary chromosomes. H. formosensis, H. (Kaiseriana) bispinosa, H. (Haemaphysalis) campanulata, H. (H.) flava, H. (H.) megaspinosa, H. (H.) japonica, and H. (H.) pentalagi possess 20 autosomes plus 2 sex chromosomes in females and 20+1 sex chromosomes in males. Phylogenetic relationships within the genus Haemaphysalis are briefly discussed.     

Histology and fine structure of spermatozoa and egg passage in the female tract of Dermacentro andersoni stiles (acari-Ixodidae)

The final phase of spermiogenesis in the hard tick Dermacentor andersoni occurs in the seminal receptacle of engorged females. This phase is characterized mainly by rupture of the outer sheath of advanced spermatids at their pointed tips, and subsequent elongation as the internal column of these cells evaginates. The sheath invaginates at the opposite end to form the narrow posterior half of the sperm cell. Rupture of the endospermatophoric wall releases the large mass of contained spermatozoa, which begin migration up one or both oviducts. During the migration to the ovarian lumen, spermatozoa exhibit a propensity for active penetration of epithelial cells lining the oviducts. This phenomenon is also observed with spermatozoa in the ovarian lumen. Penetration of epithelial cells by spermatozoa is interpreted to be a response by the latter in seeking eggs for penetration and fertilization.     

Activity of phenol oxidases at the puparium formation stage in development of nineteen lozenge mutants of Drosophila melanogaster

Phenol oxidase activity of activated A₁ and A₂ (A₃) electrophoretic components from 19 lozenge mutant and three lozenge double mutant strains was compared to that of wild type flies. Melanin production by the activated A components with tyrosine as substrate was compared to activity in the same acrylamide gels with dopa as substrate. Melanin production decreased, first in the A₁ band and then in the A₂ (A₃) band, with increased morphological expression of the mutant genes. No melanin bands were obtained with either substrate in five of the more severely affected mutants. A possible correlation between phenol oxidase activity and quinone production necessary for normal development of eyes, female accessory sex organs, and claws is discussed.Supported by PHS grant AM-08331-05.     

Juvenile Pernicious Anaemia and Hypothyroidism. A Family Study

A man presented with the sudden onset of pernicious anaemia at the age of 21. He had been treated for hypothyroidism since the age of 6. His father and only paternal aunt were also found to have pernicious anaemia. Gastric and thyroid antibody studies showed one or more antibodies to be present in all three subjects, as well as in the patient''s mother.     

Foot-and-Mouth Disease Virus: Stability of Neutralizing Antibody After Freeze-drying and Air-drying

It is possible to stabilize foot-and-mouth disease antiserum by either freeze-drying in bottles or air-drying on paper for periods of 7 months.     

Treatment of acute otitis media: a controlled study of 142 children

Results of the use of ampicillin, penicillin G and symptomatic therapy in the treatment of acute otitis media in 142 children were compared. Antibiotic therapy conveyed significant benefit. No major differences were observed between penicillin and ampicillin, except in the age group under 3 years where ampicillin was associated with the best results. Ampicillin appears to be the drug of choice. Its superiority over symptomatic therapy was statistically significant. Long-term sequelae were not observed in any of the three treatment groups. The relative merits of erythromycin and ampicillin require further study.