Role of actin in the cAMP-dependent activation of sodium/glucose cotransporter in renal epithelial cells

We examined whether actin filaments are involved in the cAMP-dependent activation of a high affinity sodium/glucose cotransporter (SGLT1) using epithelial expression systems. The expression of enhanced green fluorescent protein-tagged SGLT1 (EGFP-SGLT1) in Madin-Darby canine kidney (MDCK) cells was revealed by Western blotting and confocal laser microscopy. 8-Br-cAMP, a membrane permeable cAMP analog, enhanced [¹⁴C]-α-methyl glucopyranoside ([¹⁴C]-AMG) uptake. Both basal and 8-Br-cAMP-elicited [¹⁴C]-AMG uptakes were inhibited by N-(2{[3-(4-bromophenyl)-2-propenyl]-amino}-ethyl)-5-isoquinolinesulfonamide (H-89), a protein kinase A inhibitor, and cytochalasin D, an actin filament formation inhibitor. Furthermore, cytochalasin D inhibited the distribution of EGFP-SGLT1 at the apical surface. These results suggest that the EGFP-SGLT1 protein is functionally expressed in the apical membrane of MDCK cells, and is up-regulated by a cAMP-dependent pathway requiring intact actin filaments.     

Effects of delayed mating on preimplantation embryos in spontaneously ovulated mice

The effects of delayed mating on mouse preimplantation embryos (78 ± 1 hours) were studied by setting up different mating periods in relation to the estimated time of spontaneous ovulation. Copulation occurred even in the late morning and early afternoon after the night of spontaneous ovulation. However, females mated in the early afternoon had no viable embryos at the time of laparotomy. Although embryonic development was not affected in the groups mated 6 or 10 hours after estimated ovulation, the percentage of degenerated embryos was increased in these groups. These results suggest that prolonged intervals between the estimated time of ovulation and mating have some deleterious effects on preimplantation embryos.     

Analysis of the mode of antigen presentation required for triggering of T cell proliferation by using various azobenzenearsonate-tyrosine derivatives

Various azobenzenearsonate-tyrosine (ABA-Tyr) derivatives were synthesized by modifying amino and carboxyl groups at the alpha-carbon of tyrosine, with preservation of most of the ABA-Tyr moiety (ABA plus hydroxyphenyl portion of tyrosine). These derivatives were tested for the ability to stimulate ABA-L-Tyr specific T cell lines derived from B10.BR and B10.S mice. ABA-acetyltyramine, ABA-hydroxyphenylpropionic acid (ABA-PPr), and ABA-propylphenol, which lack either the carboxyl or amino group or both, could not induce T cell proliferation. The lack of stimulation by these derivatives was not due to their cytotoxic effects. A similar pattern of proliferation was obtained on stimulating lymph node T cells from B10.BR and B10.S mice primed with ABA-L-Tyr. Some differences were observed, however, between B10.BR and B10.S mice. ABA-L-Tyr-specific T cells from B10.BR mice could not respond well to ABA-D-Tyr in contrast to B10.S T cells. Furthermore, B10.BR mice primed with ABA-acetyltyramine or ABA-PPr in complete Freund's adjuvant could not induce ABA-L-Tyr-reactive T cells, whereas T cells from B10.S mice primed with these derivatives could proliferate in the presence of ABA-L-Tyr. The differences between B10.BR and B10.S mice were further investigated by using (B10.S X B10.BR)F1 mice. T cells from ABA-L-Tyr-immunized F1 mice responded poorly to ABA-D-Tyr when presented with B10.BR antigen-presenting cells (APC), but responded well when presented with B10.S APC. Similarly, T cells from ABA-PPr-primed F1 mice did not proliferate to ABA-L-Tyr in the presence of B10.BR APC, but could proliferate in the presence of B10.S APC. Our results clearly indicate that the presence of charged groups at the alpha-carbon of tyrosine plays a critical role in the triggering of ABA-L-Tyr-specific T cell proliferation. The significance of these results is discussed.     

Hyperthermic treatment of chromomycosis with disposable chemical pocket warmers

A case of chromomycosis in which hyperthermia proved effective is reported. The patient was a 56-year-old male bean curd maker who, without any previous history of minor trauma, developed on the extensor side of the left upper arm an eczematous lesion that underwent gradual radial expansion. The lesion showed a well-defined, 7×10 cm infiltrated erythematous plaque with the central area healed and, at the upper and lower borders, adherent scales and crusts on the surface. Histological examination revealed granulomatous changes in the dermis, as well as sclerotic cells within giant cells and microabscesses. On culturing,Fonsecaea pedrosoi was isolated. The patient was treated with disposable chemical pocket warmers, which were secured over the lesion with a rather tight elastic bandage, so that they kept the affected area warm for 24 hours a day. After a month of such hyperthermic treatment, the erythema and infiltration had decreased considerably, and microscopic examination and culture of the crusts both yielded negative results. Examination of biopsy specimens of the lesion after the third month showed that it had cicatrized. The treatment was stopped after 4 months, and no relapse occurred. We also summarize the published results of local hyperthermic treatment of chromomycosis in Japan.     

Nesting behavior of the semi-aquatic spider wasp,Anoplius eous,which transports its prey on the surface film of water (Hymenoptera,Pompilidae)

Anoplius eous Yasumatsu (Hymenoptera, Pompilidae) exhibits some outstanding nesting behavior. Females excavate a unicellular or multicellular nest in wet ground, or dig a single-celled nest in rotten wood, or build clustered mud cells in narrow spaces between walls of such substances as wood or vinyl sheets. The latter nest-type has been unknown within the subfamily Pompilinae. Females prepare a nest-cell before hunting, and construct it further after hunting, leaving the prey near the nest (behavior-formula: IVPTIOC). They transport their prey backward on the ground, grasping it in their mandibles by any part of the legs, and forward on the surface film of water or on the ground, grasping it by the middle part of the 1st or 2nd legs. Their only prey is the adult female semi-aquatic spider,Pardosa pseudoannulata (Lycosidae). These nesting and provisioning behavior patterns are compared with those of other pompilids. The position of the present species in the behavioral evolution of the Pompilidae is suggested.     

Changes in Volatile C6-Aldehydes Emitted from and Accumulated in Tea Leaves

C₆-Aldehydes emitted from intact tea leaves were analyzed quantitatively.Emission of the aldehydes increased temporarily in mid-May whenenzymatic activities involved in aldehyde formation from lipidsbegan to increase. Levels of C₆-aldehydes in tea leaves alsoincreased temporarily. However, the accumulated C₆-aldehydesdid not always correspond to emitted ones. (Received December 1, 1991; Accepted March 18, 1992)     

Decrease of palmitoyl-CoA elongation in platelets and leukocytes in the patient of hereditary methemoglobinemia associated with mental retardation

Effect of the deficiency of NADH-cytochrome b5 reductase on fatty acid elongation was studied in the platelets and leukocytes taken from a patient of hereditary methemoglobinemia associated with mental retardation. The activity of fatty acid elongation was determined by measuring the incorporation of [2-14C]malonyl-CoA into palmitoyl-CoA. The de novo biosynthesis of fatty acids was blocked by the addition of phosphotransacetylase, and the elongation system could be assayed in the homogenates separated from de novo biosynthesis. As compared to normal subjects approximately 40% decrease of fatty acid elongation was observed both in the platelets and leukocytes from the patient.     

Method of separating mouse platelets by discontinuous sucrose-gradient centrifugation

A discontinuous sucrose gradient was employed in the separation of mouse blood platelets using a modified Booyse method. The platelets of male CD-1 mice aged 8 to 12 weeks were divided into five distinct populations (A, B, C, D & E). Distribution of light to heavy platelets patterns in 10 normal CD-1 mice was demonstrable at; A (S.G. 1.188), as 14.8 +/- 5.6%; B (S.G. 1.199), 44.0 +/- 4.6%; C (S.G. 1.207), 24.1 +/- 3.4%; D (S.G. 1.214), 13.0 +/- 3.6%; and E (S.G. 1.221), 4.0 +/- 1.5%.