[Extension of life-span of normal human fibroblasts by reconstitution of telomerase activity]

Most of normal human somatic cells can divide only a finite number of times and inevitably become senescent. Telomerase is an enzyme that imparts replicative immortality by maintaining the length of the telomeres when expressed in reproductive and cancer cells. Cells that are mortal do not express the telomerase. Recently it was reported that the life-span of the normal human cells could be successfully extended by introduction of telomerase into these cells. We have found, in the previous work, that fibroblasts exhibited an osteogentic potential, and therefore, can be considered as a type of "seed cells" in tissue engineering for bone repairing and reconstruction. But this potential was impaired by the limitation in life-span and proliferative capacity of the normal fibroblasts. In the present work, plasmid pGRN145 bearing a cDNA insert of human telomerase reverse transcriptase (hTERT) was introduced into the fibroblasts with osteogenic potential by electroporation. The stable hTERT+ fibroblast clones was established and cultured for long-term in a medium containing hygromycin-B. The exogenous hTERT mRNA expression and telomerase activity were detected. The hTERT+ fibroblasts showed shorter population doubling time and no beta-galactosidase stain, which indicated a stronger proliferative capacity and fewer signs of cell senescence, compared to their hTERT- counterpart. These evidenced that the life-span of hTERT+ fibroblasts was extended. The assays for DNA euploidy by flow cytometry and chromosome karyotype by cytogenetic technique showed no signs of heteroploidy, providing the data for cell carcinogenesis and utilization safety. The results of the present study suggested that the introduction of hTERT could make the life-span of normal fibroblast extended without causing their malignant transformation, and such type of "longevous" fibroblasts might be clinically useful in tissue engineering for bone repairing and reconstruction.

[Effect of cadmium on apoptosis of spermatogenic cells of rat testis and the protection effect of zinc against it]

To study the effect of cadmium on the apoptosis of spermatogenic cells of rat testis and the protective effect of zinc against it. 24 Wistar male rats were divided into 3 groups (cadmium, cadmium and zinc, and control rats). Rats were injected with low-dose CdCl2 (2 mg/kgBW), zinc acetate(ZnAc, 15 mg/kgBW) before and after injected with low-dose CdCl2 and ZnAc(50 mg/kgBW). The control rats were injected with same-dose of 0.9% NaCl. After 7 days, the apoptosis of spermatogenic cells was studied with in situ nick translation(ISNT) technique. Compared with control group, the number of apoptosis spermategenic cells was obviously increased in cadmium group(P < 0.01, t = 3.87), but it was not significantly different in cadmium and zinc rats. Cadmium treatment could accelerate testis apoptosis. Zinc could proven it.

P16 overexpression in pituitary adenomas studied by immunohistochemistry and in situ hybridization

OBJECTIVES

To examine the expression of p16 gene and the clinicopathological characteristics of 31 pituitary adenomas. To investigate the relationship between p16 expression and cell proliferative activity by analyzing the expression of proliferating cell nuclear antigens (PCNA).

METHODS

Immunohistochemistry and in situ hybridization were performed on freshly-prepared paraffin-embedded specimens of 31 pituitary adenomas.

RESULTS

Varying degrees of overexpression of the p16 gene was found in the tumors specimens. A higher proportion of p16 positive tumor cells was associated with bigger size, more frequent invasion and higher recurrence of the tumors. The expression of p16 was found to be significantly associated with the degree of PCNA expression.

CONCLUSION

Though inactivation of the p16 gene is known in wide range of tumors, our study suggested that p16 overexpression might play a role in the development and progression of pituitary adenomas.

Establishment and characterization of an Oklahoma isolate of Anaplasma marginale in cultured Ixodes scapularis cells

Anaplasma marginale is a tick-borne hemoparasite of cattle worldwide. The Virginia isolate of A. marginale was propagated previously in a cell line derived from embryos of the tick, Ixodes scapularis. The cultured Anaplasma (VA-tc) was passaged continuously for over 4 years and retained its infectivity for cattle and antigenic stability. We report herein the continuous in vitro cultivation of a second isolate of A. marginale derived from a naturally infected cow in Oklahoma (OK-tc). Blood from the infected cow was subinoculated into a splenectomized calf and blood collected at peak parasitemia was frozen, thawed and used as inoculum on confluent tick cell monolayers. Colonies of Anaplasma were apparent in low numbers at 9 days post exposure (PE) and infection in monolayers reached 100% by 4-5 weeks PE. Cultures were passaged by placing supernatant onto fresh tick cell monolayers at a dilution of 1:5 or 1:10. By the third passage development of the OK-tc was similar to that of the VA-tc and a 1:5 dilution resulted in 100% infection in 10-12 days. Inoculation of OK-tc into a splenectomized calf caused clinical anaplasmosis and Dermacentor ticks that fed on this calf transmitted the organism to a second susceptible calf. Major surface proteins (MSPs) 1-5 of the OK-tc were compared with homologous proteins present on VA-tc and the erythrocytic stage of the Oklahoma isolate. The MSPs 1, 2, 4, 5 were conserved on the OK-tc but there was evidence for structural variation in MSP3 between the cultured and erythrocytic stage of Anaplasma. MSP2 and MSP3 were the major proteins recognized by serum from infected cattle. Two-dimensional gels also identified positional differences between VA-tc and OK-tc in MSP2 and MSP3. The OK-tc may have potential to be used as antigen for development of an improved vaccine for anaplasmosis in the South Central United States.

Expression, purification and characterization of recombinant mouse MT5-MMP protein products

We have recently identified the fifth member of the membrane-type matrix metalloproteinase subfamily, MT5-MMP/MMP24, which is expressed in a brain specific manner (Duanqing Pei (1999) J. Biol. Chem. 274, 8925-8932). To further characterize its enzymic properties, an expression construct was engineered to produce MT5-MMP as a soluble and active form by truncating its transmembrane domain. Stable expression cell lines were subsequently established from MDCK cells transfected with this construct. Unfortunately, purification of MT5-MMP from the culture media in large quantity proves to be difficult initially due to its rapid turnover via a mechanism which can be inhibited by a broad spectrum metalloproteinase inhibitor, BB94. Thus, BB94 was included in the cell culture medium and throughout the purification process except the final step of chromatography to protect MT5-MMP from destruction. Purified to homogeneity and free of the synthetic inhibitor, MT5-MMP can activate progelatinase A efficiently in a TIMP2 sensitive fashion. A preliminary screen for its potential substrates among extracellular matrix components identified the proteoglycans as the preferred substrates for MT5-MMP. Furthermore, it is determined that the stability of purified MT5-MMP is temperature dependent with rapid destruction at 37 degrees C, but being relatively stable at temperatures 4 degrees C or lower. These observations establish MT5-MMP as a proteoglycanase with a short half-life at body temperature, which may be critical for tightly controlled turnover of ECM components such as those in the brain.

The convergent point of the endocytic and autophagic pathways in leydig cells

Endocytic tracers and marker enzyme of lysosomes were used in the present study to analyze the processes of autophagocytosis and endocytosis, and the convergent point of these two pathways in Leydig cells. The endocytic and autophagic compartments can be easily identified in Leydig cells, which makes easier to define the stages of two pathways than was possible before. The evidences indicated that the late endosomes (dense MVBs) deliver their endocytosed gold tracers together with lysosomal enzymes to the early autophagosomes and they are the convergent point of the two pathways. During this convergent process, the early autophagosomes transform into late autophagosomes and the late endosomes transform into mature lysosomes.

Divalent cations stimulate preferential recognition of a viral DNA end by HIV-1 integrase

In the presence of a divalent metal cofactor (Mg2+ or Mn2+), retroviral-encoded integrase (IN) catalyzes two distinct reactions: site-specific cleavage of two nucleotides from both 3' ends of viral DNA, and sequence-independent joining of the recessed viral ends to staggered phosphates in a target DNA. Here we investigate human immunodeficiency virus type 1 (HIV-1) IN-DNA interactions using surface plasmon resonance. The results show that IN forms tight complexes both with duplex oligonucleotides that represent the viral DNA ends and with duplex oligonucleotides with an unrelated sequence that represent a target DNA substrate. The IN-DNA complexes are stable in 4.0 M NaCl, or 50% (v/v) methanol, but they are not resistant to low concentrations of SDS, indicating that their stability is highly dependent on structural features of the protein. Divalent metal cofactors exert two distinct effects on the IN-DNA interaction. Mn2+ inhibits IN binding to a model target DNA with the apparent Kd increasing approximately 3-fold in the presence of this cation. On the other hand, Mn2+ (or Mg2+) stimulates the binding of IN to a model viral DNA end, decreasing the apparent Kd of this IN-viral DNA complex approximately 6-fold. Such metal-mediated stimulation of the binding of IN to the viral DNA is totally abolished by substitution of the subterminal conserved CA/GT bp with a GT/CA bp, and is greatly diminished when the viral DNA end is recessed or "pre-processed." IN binds to a viral duplex oligonucleotide whose end was extended with nonviral sequences with kinetics similar to the nonviral model target DNA. This suggests that IN can distinguish the integrated DNA product from the viral donor DNA in the presence of divalent metal ion. Thus, our results show that preferential recognition of viral DNA by HIV-1 IN is achieved only in the presence of metal cofactor, and requires a free, wild-type viral DNA end.

Efficient diffusive reflector-type diode side-pumped Nd:YAG rod laser with an optical slope efficiency of 55%

We fabricated a compact diode side-pumped Nd:YAG laser with a diffusive reflector, in which the diode laser power is transferred directly into the threefold symmetric diffusive cavity through long narrow slits. With a 7.5% output coupler in a linear resonator, we obtained 62.4-W multimode output power with an optical slope efficiency of 53.4% at a diode power of 182 W, which corresponds to an optical-to-optical efficiency of 34.3%. The optical slope efficiency increased to 55.5% when we used an 11% output coupler. From the leakage power analysis method, the pumping efficiency was measured to be approximately 82%. We discuss the thermal lens and the slope efficiency with respect to absorbed power that is derived from the measured pumping efficiency.

[Studies on localization of laryngeal carcinoma associated antigen by immunoelectromicroscopy]

OBJECTIVE

To study the localization of laryngeal carcinoma associated antigen (LCAA) in the carcinoma tissue.

METHODS

Ninety cases of laryngeal carcinoma and 14 cases of laryngeal precancerous lesion and 10 cases of normal laryngeal mucosa were detected with three strains of monoclonal antibodies LC9, LC11, LC12 by immunochemistry. The positive sections of laryngeal carcinoma were observed under light microscope and electromicroscopy.

RESULTS

The positive rates of LCAA were dramatically higher than that in normal epithelial and precancerous tissues (P < 0.01). The results showed that the mixed monoclonal antibody had tissue specificity. The MLC associated antigens only distributed in cell membranes and/or cytoplasm. No cell nucleus was stained.

CONCLUSION

The LCAA is mainly located in cell membranous structure. This study may provide morphological basis for immunoimaging diagnosis and targeting chemotherapy by application of laryngeal carcinoma McAb.

Comparison of surface proteins of Anaplasma marginale grown in tick cell culture, tick salivary glands, and cattle

Anaplasma marginale, a tick-borne rickettsial pathogen of cattle, infects bovine erythrocytes, resulting in mild to severe hemolytic disease that causes economic losses in domestic livestock worldwide. Recently, the Virginia isolate of A. marginale was propagated in a continuous tick cell line, IDE8, derived from embryonic Ixodes scapularis. Development of A. marginale in cell culture was morphologically similar to that described previously in ticks. In order to evaluate the potential of the cell culture-derived organisms for use in future research or as an antigen for serologic tests and vaccines, the extent of structural conservation of the major surface proteins (MSPs) between the cell culture-derived A. marginale and the bovine erythrocytic stage, currently the source of A. marginale antigen, was determined. Structural conservation on the tick salivary-gland stage was also examined. Monoclonal and monospecific antisera against MSPs 1 through 5, initially characterized against erythrocyte stages, also reacted with A. marginale from cell culture and tick salivary glands. MSP1a among geographic A. marginale isolates is variable in size because of different numbers of a tandemly repeated 28- or 29-amino-acid peptide. The cell culture-derived A. marginale maintained the same-size MSP1a as that found on the Virginia isolate of A. marginale in bovine erythrocytes and tick salivary glands. Although differences were observed in the polymorphic MSP2 antigen between culture and salivary-gland stages, MSP2 did not appear to vary, by two-dimensional gel electrophoresis, during continuous passage in culture. These data show that MSPs of erythrocyte-stage A. marginale are present on culture stages and may be structurally conserved during continuous culture. The presence of all current candidate diagnostic and vaccine antigens suggests that in vitro cultures are a valuable source of rickettsiae for basic research and for the development of improved diagnostic reagents and vaccines against anaplasmosis.

Visualization of sulfated glycoconjugates in the chicken embryonic heart by whole-mount alcian blue staining

In the atrioventricular canal (AVC) and outflow tract (OT) of the developing heart, endothelial cells transform specifically to mesenchymal cells. The mesenchymal cells migrate into the underlying acellular matrix termed cardiac jelly and form endocardial cushion tissue. It is believed the that the highly hydrated nature of cardiac jelly is ascribed to sulfated glycoconjugates in the components of jelly matrix. In the present study, we have visualized the distribution and its temporal changes of sulfated glycoconjugates in the embryonic heart from stage 12 to 26 using whole mount alcian blue (AB) histochemistry. Atrial matrix was AB-negative in all the stages examined. Cardiac jelly in the AVC and OT were positive and the staining intensity increased as heart development proceeded, while AB-positive staining in the matrix of the ventricle became negative by stage 19. At stages later than 19, AB-positive matrix was localized in only the AVC and OT where endothelially-derived mesenchymal cells populated.

Molecular cloning and functional expression of a skeletal muscle dihydropyridine receptor from Rana catesbeiana

In skeletal muscle the dihydropyridine receptor is the voltage sensor for excitation-contraction coupling and an L-type Ca2+ channel. We cloned a dihydropyridine receptor (named Fgalpha1S) from frog skeletal muscle, where excitation-contraction coupling has been studied most extensively. Fgalpha1S contains 5600 base pairs coding for 1688 amino acids. It is highly homologous with, and of the same length as, the C-truncated form predominant in rabbit muscle. The primary sequence has every feature needed to be an L-type Ca2+ channel and a skeletal-type voltage sensor. Currents expressed in tsA201 cells had rapid activation (5-10 ms half-time) and Ca2+-dependent inactivation. Although functional expression of the full Fgalpha1S was difficult, the chimera consisting of Fgalpha1S domain I in the rabbit cardiac Ca channel had high expression and a rapidly activating current. The slow native activation is therefore not determined solely by the alpha1 subunit sequence. Its Ca2+-dependent inactivation strengthens the notion that in rabbit skeletal muscle this capability is inhibited by a C-terminal stretch (Adams, B., and Tanabe, T. (1997) J. Gen. Physiol. 110, 379-389). This molecule constitutes a new tool for studies of excitation-contraction coupling, gating, modulation, and gene expression.

A high-level mammalian expression system based on the Madin-Darby canine kidney cell line

In this report, we demonstrate that a combination of the Madin-Darby canine kidney (MDCK) cell line and a cytomegalovirus promoter-based expression vector can achieve high-level expression of secretory recombinant proteins in mammalian cells. The matrix metalloproteinase MMP13, a secretory protein, was expressed in MDCK cells at a level high enough to be detectable in crude supernatants without concentration on sodium dodecyl sulfate-polyacrylamide gel electrophoresis stained with Coomassie brilliant blue R-250. The secreted MMP-13 accounts for about 15 to 20% of the total secreted proteins and reaches a concentration of at least 10 mg/liter of unconcentrated conditioned medium harvested from confluent monolayer culture. Furthermore, the recombinant protein appears to be properly folded and modified posttranslationally. This system may be employed for the production of human proteins of special interests, such as those for structural determination or therapeutical development.

Regulation of thiamin diphosphate-dependent 2-oxo acid decarboxylases by substrate and thiamin diphosphate.Mg(II) - evidence for tertiary and quaternary interactions

The regulatory mechanism of substrate activation in yeast pyruvate decarboxylase is triggered by the interaction of pyruvic acid with C221 located on the beta domain at >20 A from the thiamin diphosphate (ThDP). To trace the putative information transfer pathway, substitutions were made at H92 on the alpha domain, across the domain divide from C221, at E91, next to H92 and hydrogen bonded to W412, the latter being intimately involved in the coenzyme binding locus. Additional substitutions were made at D28, E51, H114, H115, I415 and E477, all near the active center. The pH-dependent steady-state kinetic parameters, including the Hill coefficient, provide useful insight to this effort. In addition to C221, the residues H92, E91, E51 and H114 and H115 together appear to have a critical impact on the Hill coefficient, providing a pathway for information transfer. To study the activation by ThDP.Mg(II), variants at G231 (of the conserved GDG triplet) and at N258 and C259 (all three being part of the putative ThDP fold) of the E1 component of the Escherichia coli pyruvate dehydrogenase multienzyme complex were studied. Kinetic and spectroscopic evidence suggests that the Mg(II) ligands are very important to activation of the enzymes by cofactors.

Inactivation of gating currents of L-type calcium channels. Specific role of the alpha 2 delta subunit

In studies of gating currents of rabbit cardiac Ca channels expressed as alpha 1C/beta 2a or alpha 1C/beta 2a/alpha 2 delta subunit combinations in tsA201 cells, we found that long-lasting depolarization shifted the distribution of mobile charge to very negative potentials. The phenomenon has been termed charge interconversion in native skeletal muscle (Brum, G., and E. Ríos. 1987. J. Physiol. (Camb.). 387:489-517) and cardiac Ca channels (Shirokov, R., R. Levis, N. Shirokova, and E. Ríos. 1992. J. Gen. Physiol. 99:863-895). Charge 1 (voltage of half-maximal transfer, V1/2 approximately 0 mV) gates noninactivated channels, while charge 2 (V1/2 approximately -90 mV) is generated in inactivated channels. In alpha 1C/beta 2a cells, the available charge 1 decreased upon inactivating depolarization with a time constant tau approximately 8, while the available charge 2 decreased upon recovery from inactivation (at -200 mV) with tau approximately 0.3 s. These processes therefore are much slower than charge movement, which takes <50 ms. This separation between the time scale of measurable charge movement and that of changes in their availability, which was even wider in the presence of alpha 2 delta, implies that charges 1 and 2 originate from separate channel modes. Because clear modal separation characterizes slow (C-type) inactivation of Na and K channels, this observation establishes the nature of voltage-dependent inactivation of L-type Ca channels as slow or C-type. The presence of the alpha 2 delta subunit did not change the V1/2 of charge 2, but sped up the reduction of charge 1 upon inactivation at 40 mV (to tau approximately 2 s), while slowing the reduction of charge 2 upon recovery (tau approximately 2 s). The observations were well simulated with a model that describes activation as continuous electrodiffusion (Levitt, D. 1989. Biophys. J. 55:489-498) and inactivation as discrete modal change. The effects of alpha 2 delta are reproduced assuming that the subunit lowers the free energy of the inactivated mode.

Method for determining the two-beam coupling gain coefficients of photorefractive crystals

A new method is proposed for determining the two-beam coupling gain coefficients of photorefractive crystals with both o- and e-polarized lights. This method enables one to determine simultaneously and precisely the gain coefficients of a crystal for o- and e-polarized lights while the fanning effect is diminished. Experimental demonstrations are presented.

The human TRIP6 gene encodes a LIM domain protein and maps to chromosome 7q22, a region associated with tumorigenesis

The thyroid receptor interacting protein-6 (TRIP6) was first identified as a ligand-dependent binding partner for the thyroid hormone receptor in a yeast two-hybrid screen. A partial TRIP6 cDNA clone that was isolated in the initial screen encodes two copies of the LIM domain. The LIM domain is a double zinc-finger structure that mediates protein-protein interactions. Here we report the complete amino acid sequence of human TRIP6. The TRIP6 protein displays a proline-rich N-terminal region linked to three tandemly arrayed C-terminal LIM domains. The global molecular architecture and sequence of TRIP6 place it in the same family as the adhesion plaque protein, zyxin, and the lipoma preferred partner (LPP). Zyxin and LPP are implicated in cellular signaling and tumorigenesis, respectively. By radiation hybrid mapping, the human TRIP6 gene was assigned to a segment of chromosome 7q22 that is commonly deleted in malignant myeloid diseases and uterine leiomyoma.

Endothelial outgrowth and the subsequent cell transition in the culture of embryonic atrioventricular canal placed in an inverted polarity

Endothelial cells in the atrioventricular (AV) segment of the developing chicken heart undergo a transition into mesenchymal cells. When the AV segment is explanted onto a hydrated collagen gel, endothelial cells grow out and reproduce in vivo cell transition regardless of the precise orientation of the explant on a gel. Our results showed that when the luminal side of an explant was placed towards a gel surface, the inverted polarity of endothelium was not adjusted by direct reorganization of polarity, but that the endothelium crawled down so as to settle on a gel surface in the correct original cell polarity. Subsequently, endothelial cells showed cytoplasmic hypertrophy, formed microvillous projections and then extended filopodial migratory appendages. These cellular changes were quite similar to those in vivo. However, the continuity of the endothelial layer was specifically disrupted in AV explant cultures. Such disruption was never observed in ventricle explant cultures in which endothelial-mesenchymal cell transition did not occur. The disintegration of AV endothelial outgrowth must be closely related to its capability to transform into mesenchymal cells and mitotic activity to keep a depository of endothelial cells.

Systematic study of the six cysteines of the E1 subunit of the pyruvate dehydrogenase multienzyme complex from Escherichia coli: none is essential for activity

Variants of the Escherichia coli 1-lip pyruvate dehydrogenase multienzyme complex (1-lip PDHc) with the C259N and C259S substitutions in the putative thiamin diphosphate-(ThDP-) binding motif of the pyruvate dehydrogenase component (E1, EC 1.2.4.1) were characterized. Single substitutions were made at the five remaining cysteines of the E1 component, creating the C120A, C575A, C610A, C654A, and C770S variants to test the hypothesis that the activity loss that accompanies exposure of the enzyme to fluoropyruvate, bromopyruvate, and 2-oxo-3-butynoic acid is the result of the modification of approximately one cysteine residue per E1 monomer. Surprisingly, all single cysteine E1 variants could be reconstituted with E2-E3 subcomplex and showed PDHc activity ranging from 74% to 96% that of the parental enzyme. The specific activities of C259N and C259S variants of 1-lip PDHc were 58% and 27% relative to that of the parental 1-lip PDHc. All five single cysteine E1 variants, along with the C259N and C259S variants of 1-lip PDHc, could also (1) be inactivated with fluoropyruvate and 2-oxo-3-butynoic acid, (2) were subject to inactivation by the monoclonal antibody 18A9 reported from one of our laboratories, and (3) were subject to regulation by pyruvate and acetyl-CoA. It was therefore concluded that none of the six cysteine residues is essential for the activity of the E1 component or of the complex. When tested with the putative transition-state analogue, thiamin 2-thiothiazolone diphosphate, all but the C259S and C259N variants were very potently inhibited, the stoichiometry for parental E1 being about 1.6 mol of inhibitor/mol of E1 subunit. The C259S and C259N E1 variants required at least 25-fold greater inhibitor concentration to achieve the same level of inhibition. C259 is located in the putative thiamin diphosphate-binding motif of the enzyme [more exactly, it is adjacent to a ligand to the Mg(II) ion]. It is therefore concluded that thiamin 2-thiothiazolone diphosphate is not a transition-state analogue; rather, it is a potent inhibitor of the complex because of a specific interaction with the C259 residue.

[Indigenous hydroxyapatite as a successful anophthalmic orbital implant]

OBJECTIVE

The aim of the work was to improve the operative result of eye socket reconstruction after enucleation.

METHODS

The hydroxyapa tite implant of eyeball shape was buried in the scleral shell, which was stitched to the extraocular muscles at the points of muscle attachment so as to create a rotatable eye seat connector.

RESULTS

One hundred and two patients have received eye socket reconstruction of this method with improved results. The prosthetic eyes move freely. Follow-up for 6 to 38 months reveals that the results are stable and satisfactory.

CONCLUSION

The indigenous hydroxyapa tite implant is a good biomaterial for socket reconstruction.

2-Oxo-3-alkynoic acids, universal mechanism-based inactivators of thiamin diphosphate-dependent decarboxylases: synthesis and evidence for potent inactivation of the pyruvate dehydrogenase multienzyme complex

A new class of compounds, the 2-oxo-3-alkynoic acids with a phenyl substituent at carbon 4 was reported by the authors as potent irreversible and mechanism-based inhibitors of the thiamin diphosphate- (ThDP-) dependent enzyme pyruvate decarboxylase [Chiu, C.-F., & Jordan, F. (1994) J. Org. Chem. 59, 5763-5766]. The method has been successfully extended to the synthesis of the 4-, 5-, and 7-carbon aliphatic members of this family of compounds. These three compounds were then tested on three ThDP-dependent pyruvate decarboxylases: the Escherichia coli pyruvate dehydrogenase multienzyme complex (PDHc) and its E1 (ThDP-dependent) component, pyruvate oxidase (POX, phosphorylating; from Lactobacillus plantarum),and pyruvate decarboxylase (PDC) from Saccharomycescerevisiae. All three enzymes were irreversibly inhibited by the new compounds. The 4-carbon acid is the best substrate-analog inactivator known to date for PDHc, more potent than either fluoropyruvate or bromopyruvate. The following conclusions were drawn from extensive studies with PDHc: (a) The kinetics of inactivation of PDH complexes and of resolved E1 by 2-oxo-3-alkynoic acids is time- and concentration-dependent. (b) The 4-carbon acid has a Ki 2 orders of magnitude stronger than the 5-carbon acid, clearly demonstrating the substrate specificity of PDHc. (c) The rate of inactivation of PDH complexes and of resolved E1 by 2-oxo-3-alkynoic acids is enhanced by the addition of ThDP and MgCl2. (d) Pyruvate completely protects E1 and partially protects PDHc from inactivation by 2-oxo-3-butynoic acid. (e) E1 but not E2-E3 is the target of inactivation by 2-oxo-3-butynoic acid. (f) Inactivation of E1 by 2-oxo-3-butynoic acid is accompanied by modification of 1.3 cysteines/E1 monomer. The order of reactivity with the 4-carbon acid was PDHc > POX > PDC. While the order of reactivity with PDHc and POX was 2-oxo-3-butynoic acid > 2-oxo-3-pentynoic acid > 2-oxo-3-heptynoic acid, the order of reactivity was reversed with PDC.

Ion-dependent inactivation of barium current through L-type calcium channels

It is widely believed that Ba2+ currents carried through L-type Ca2+ channels inactivate by a voltage-dependent mechanism similar to that described for other voltage-dependent channels. Studying ionic and gating currents of rabbit cardiac Ca2+ channels expressed in different subunit combinations in tsA201 cells, we found a phase of Ba2+ current decay with characteristics of ion-dependent inactivation. Upon a long duration (20 s) depolarizing pulse, IBa decayed as the sum of two exponentials. The slow phase (tau approximately 6 s, 21 degrees C) was parallel to a reduction of gating charge mobile at positive voltages, which was determined in the same cells. The fast phase of current decay (tau approximately 600 ms), involving about 50% of total decay, was not accompanied by decrease of gating currents. Its amplitude depended on voltage with a characteristic U-shape, reflecting reduction of inactivation at positive voltages. When Na+ was used as the charge carrier, decay of ionic current followed a single exponential, of rate similar to that of the slow decay of Ba2+ current. The reduction of Ba2+ current during a depolarizing pulse was not due to changes in the concentration gradients driving ion movement, because Ba2+ entry during the pulse did not change the reversal potential for Ba2+. A simple model of Ca(2+) -dependent inactivation (Shirokov, R., R. Levis, N. Shirokova, and F., Ríos. 1993. J. Gen. Physiol. 102:1005-1030) robustly accounts for fast Ba2+ current decay assuming the affinity of the inactivation site on the alpha 1 subunit to be 100 times lower for Ba2+ than Ca2+.

Biotin and digoxigenin as labels for light and electron microscopy in situ hybridization probes: where do we stand?

Biotin was recently applied to detect cellular DNA or RNA. In combination with avidin, streptavidin or antibody, it can be conjugated with fluorescent dye, enzyme, ferritin, or gold. However, emphasis has recently been placed on the false-positive results that are obtained when this probe is used, because endogenous biotin may sometimes interfere with specific signals. Digoxigenin appears to be an interesting alternative because it is present exclusively in Digitalis plants as a secondary metabolite. We discuss in this review the efficiency and the respective advantages and disavantages of these two probes for in situ hybridization, mainly at the electron microscopic level.

Effect of substitutions in the thiamin diphosphate-magnesium fold on the activation of the pyruvate dehydrogenase complex from Escherichia coli by cofactors and substrate

The homotropic regulation of the Escherichia coli pyruvate dehydrogenase multienzyme complex (PDHc) by its coenzyme thiamin diphosphate and its substrate pyruvate was re-examined with complexes containing three and one lipoyl domains per E2 chain, and several variants of the latter, containing substitutions in the putative thiamin diphosphate fold of E1 (G231A, G231S, C259S, C259N, and N258Q). It was found that all of the E1 variants had significantly reduced specific activities, as reported elsewhere (Russell, G. C., Machado, R. S., and Guest, J. R. (1992) Biochem. J. 287, 611-619). In addition, extensive kinetic studies were performed in an attempt to determine the effects of the amino acid substitutions on the Hill coefficients with respect to thiamin diphosphate and pyruvate. All but one of the variants were incapable of being saturated with thiamin diphosphate, even at concentrations > 5 mM. Most importantly, the striking activation lag phase lasting for many seconds in the parental complexes containing three and one lipoyl domains per E2 chain was totally eliminated in the variants. Furthermore, activation by the coenzyme was localized to the E1 subunit, because resolved E1 exhibits virtually the same behavior during the activation lag phase as does the complex. In the parental complexes two distinct lag phases could be resolved, the duration of both decreases with increasing ThDP concentration. A mechanism that is consistent with all of the kinetic data on the parental complexes involves rapid equilibration of the first ThDP with the E1 dimer, followed by a slow conformational equilibration, that in turn is followed by slow addition of the second ThDP to form the fully activated dimer. When the diphosphate site is badly impaired, the binding affinity is very much reduced, this perhaps eliminates the slow step leading to the activated dimer form of the E1.

Alterations in glutathione homeostasis in mutant Eisai hyperbilirubinemic rats

Eisai hyperbilirubinemic rats (EHBR) are mutant Sprague-Dawley rats that exhibit impaired biliary organic anion and reduced glutathione (GSH) secretion. In addition, liver GSH levels are twice that of age-matched controls. The mechanisms for the defect in biliary GSH secretion and the increase in cell GSH are not fully understood. We previously showed that canalicular membrane-enriched vesicles isolated from EHBR livers exhibited normal GSH transport. In the present study, we examined the steady-state rat canalicular reduced glutathione transporter (RcGshT) messenger RNA (mRNA) and protein levels, as well as the mechanisms for the increase in cell GSH. Both Northern and Western blot analyses of EHBR livers showed nearly identical RcGshT mRNA and polypeptide levels, respectively, as compared with controls. Treatment with phenobarbital, which increased steady-state RcGshT mRNA by five- to sixfold, RcGshT polypeptide, and biliary GSH secretion by onefold in controls, had a smaller effect on steady-state RcGshT-mRNA level in EHBR (by 1.5-fold) and did not increase RcGshT polypeptide or biliary GSH secretion. In examining possible mechanisms for increased liver GSH, both cysteine level and gamma-glutamylcysteine synthetase (GCS) activity were significantly higher than controls, while the activity of GSH synthetase was unchanged. Northern and Western blot analyses also showed increased steady-state GCS heavy subunit (GCS-HS) mRNA and polypeptide levels, respectively. In addition to liver, GSH levels in kidney, duodenal, jejunal, and ileal mucosa of EHBR were 200% to 300% of age-matched control rats. GCS activity was also increased in kidney cytosol of EHBR. Thus, the defect in biliary GSH secretion in EHBR most likely is either at the posttranslational level of RcGshT or in the inhibition exerted by retained endogenous organic anions. In addition, there is a widespread up-regulation of GSH synthesis capacity in the tissues of EHBR.

[Clinical application of a new mobile integrated orbital implant]

OBJECTIVE

To improve the socket reconstruction after enucleation.

METHODS

Hydroxyapatite (HA, made in China) was made into a porous HA sphere and wrapped up in the scleral shell as a mobile integrated orbital implant. It was applied to 43 patients with enucleation and anophthalmia, The surgical technique is described.

RESULTS

All sockets have been corrected very well and the prosthetic mobility and the cosmetic appearance are excellent. After a follow-up of 6 to 24 months, no migration or extrusion of the implant or infection occurred.

CONCLUSION

It is considered that at present this new mobile integrated orbital implant is made of one of the best materials and this method of socket reconstruction is one of the best method for selection.

Role of two recently cloned rat liver GSH transporters in the ubiquitous transport of GSH in mammalian cells

Recently our laboratory has cloned both the rat canalicular and sinusoidal GSH transporters (RcGshT and RsGshT, respectively; Yi, J., S. Lu, J. Fernandez-Checa, and N. Kaplowitz. 1994. J. Clin. Invest. 93:1841-1845; and 1995. Proc. Natl. Acad. Sci. USA. 92:1495-1499). The current work characterized GSH transport and the expression of these two GSH transporters in various mammalian cell lines. The average cell GSH levels (nmol/10(6) cells) were 25, 22, 32, 13, and 13 in HepG2, HeLa, CaCo-2, MDCK, and Cos-1 cells, respectively. GSH efflux was temperature dependent and averaged 0.018, 0.018, 0.012, 0.007, and 0.019 nmol/10(6) cells/min from HepG2, HeLa, CaCo-2, MDCK, and Cos-1 cells, respectively. Dithiothreitol (DTT), which stimulates rat sinusoidal GSH efflux, stimulated GSH efflux only in HepG2 and HeLa cells which was partially reversed by subsequent cystine treatment. GSH uptake (1 mM plus 35S-GSH) was temperature dependent, linear up to 45 min, and Na+-independent with average rates of 1.12, 0.91, 0.45, and 0.45 nmol/10(6) cells/30 min for HepG2, HeLa, CaCo-2, MDCK, and Cos-1 cells, respectively. BSP-GSH (2mM), which cis-inhibits sinusoidal GSH uptake in rat liver and HepG2 cells, inhibited GSH uptake only in HeLa cells. mRNA and polypeptide of RcGshT are expressed in all cells whereas those of RsGshT are expressed only in HepG2 and HeLa cells. In conclusion, bidirectional GSH transport, mediated by the "canalicular" GSH transporter, is ubiquitous in mammalian cells. Sinusoidal GSH transporter expression is more restricted, being present in HepG2 and HeLa cells. DTT and BSP-GSH affect GSH transport only in cells expressing the sinusoidal transporter confirming their selective action on this transporter.

A neural network model forecasting for prediction of daily maximum ozone concentration in an industrialized urban area

Prediction of ambient ozone concentrations in urban areas would allow evaluation of such factors as compliance and noncompliance with EPA requirements. Though ozone prediction models exist, there is still a need for more accurate models. Development of these models is difficult because the meteorological variables and photochemical reactions involved in ozone formation are complex. In this study, we developed a neural network model for forecasting daily maximum ozone levels. We then compared the neural network's performance with those of two traditional statistical models, regression, and Box-Jenkins ARIMA. The neural network model for forecasting daily maximum ozone levels is different from the two statistical models because it employs a pattern recognition approach. Such an approach does not require specification of the structural form of the model. The results show that the neural network model is superior to the regression and Box-Jenkins ARIMA models we tested.

[A double-blind parallel group study of beclomethasone dipropoinate nasal spray of two different sources in the treatment of allergic rhinitis]

In order to compare the clinical efficacy and safety of beclomethasone dipropionate nasal spray (BDNS) manufactured in Chongqing Glaxo Limited (Group A) and Glaxo UK (Group B), a randomised double-blind parallel group study was performed. A total of 204 patients with seasonal or perennial allergic rhinitis were recruited into the study for a period of 2 weeks. Overall efficacy (excellent/good) was 88% for Group A (excellent 55%) and 90% for Group B (excellent 51%) respectively. Side effects were similar for both groups where dry nose was the most common complaint (4.9% for both groups). However, there was no statistical difference (P > 0.05) between the two groups either in efficacy or side effects. Pollen count was monitored throughout the study period. Pollen season was divided into three periods, i.e. the beginning, the peak and the end. There was no statistical difference (P > 0.05) between the two groups in any period.

Electron microscopic location of mRNA in the rat kidney: improved post-embedding in situ hybridization

We determined the optimal technical conditions for post-embedding non-radioactive in situ hybridization applied to ultrastructural location of collagen I mRNA in rat kidney. The signal-to-noise ratio was improved by enhancing hybridization efficiency and distinguishing nonspecific labeling. Probes were labeled with digoxigenin or biotin and detected after hybridization by immunogold or peroxidase techniques. Under these conditions, the signal was located in fibroblasts. With digoxigenin, clusters of gold particles were observed on the endoplasmic reticulum (ER) or scattered throughout the cytoplasmic matrix and nuclei. With the enzymatic method, diaminobenzidine deposits were found on the ER but endogeneous peroxidase partly interfered with the results. Gold particles were less numerous in fibroblast cytoplasm with biotin than with digoxigenin. Moreover, gold particles condensed on fibroblast and tubular cell mitochondria when biotin was used, a phenomenon shown to be due to endogenous biotin by means of a histochemical method. The digoxigenin-immunogold system appeared to be the best method. The biotin system was subject to limitations such as interference from endogenous biotin and poor sensitivity, and mRNA localization was more precise and reliable by the immunogold method than by the enzymatic method.

Functional implication of autophagy in steroid-secreting cells of the rat

BACKGROUND

Autophagy, while frequently observed in embryonic cells undergoing differentiation and in pathologically altered cells, appears to occur less commonly in normal, fully differentiated cells. Our previous work revealed that the frequency of autophagic activity was rather high in the Leydig cells of rat testes, but the functional significance of autophagy in Leydig cells remains obscure. The purpose of the present study is to investigate the possible role of autophagy in steroid-secreting cells.

METHODS

The autophagic activity was investigated in two steroid-secreting cells, e.g., Leydig cells and adrenocortical fasciculata cells of rats. Cytidine monophosphatase (CMPase) cytochemistry was utilized to show the activity of lysosomal enzymes in autophagosomes. Electron microscopic morphometry was employed to analyze the frequencies of autophagy in the cells of the rats intact or treated with related hormones resulting in a hyper- or hypo-secretion of testosterone and corticosterone.

RESULTS

Autophagy took place in normal steroid-secreting cells with higher frequencies than in many other cells including the tubular cells of kidney and hepatocytes. The large number of autophagosomes or autophagic vacuoles allowed to outline the autophagic process in these cells. The C-shaped double-membrane profiles tending to demarcate a portion of cytoplasm were referred to as pre-autophagosomes. So-called early autophagosomes were the vacuoles enclosed completely by double delimiting membranes, containing normal-looking cellular components. The majority of sequestered organelles appeared to be mitochondria and smooth endoplasmic reticulum. The autophagosomes starting digestion were considered as late autophagosomes or autophagic vacuoles, the indications of which were the destruction of their contents or the presence of lysosomal enzymes demonstrated by a positive CMPase reaction. Residual bodies were frequently observed to be exocytosed. The quantitative assay revealed an alteration of autophagic activity in close relation with steroid-secreting states. The number of autophagosomes was one-fold higher in hyposecreting Leydig cells after 2 days testosterone administration, and three-fold higher in hyposecreting adrenocortical fasciculata cells after one dosage of dexamethasone administration. In addition, the autophagosomes showed a four-fold decrease in hypersecreting Leydig cells stimulated by LRH for 2 days.

CONCLUSIONS

Considering that most of the autophagocytosed organelles were steroid-producing apparatus, we may conclude that, by removing part of steroid-producing organelles, autophagy might play a role in adapting to or even regulating the secretory activity. This hypothesis was strongly supported by the fact that the intensity of autophagy varied in company with the fluctuation of steroid secretion.

Treatment of claustrophobias and snake/spider phobias: fear of arousal and fear of context

Forty-nine individuals with fears of snakes or spiders, and 21 individuals with claustrophobic fear were assigned randomly to two sessions of either in vivo exposure plus relaxation or in vivo exposure plus disconfirmation of misappraisals of bodily sensations. Behavioral, subjective and physiological assessments were conducted pre and post treatment, and 4 weeks later. As hypothesized, disconfirmation of misappraisals of bodily sensations benefited claustrophobic fear reduction, but had little effect on fears of snakes or spiders. However, differential treatment effects failed to generalize to nontargetted phobic situations, or generalize over time. In addition, the two treatments affected basic beliefs about arousal sensations equally.

Quantification of the extent and severity of perfusion defects in canine myocardium by PET polar mapping

This study validates perfusion defect extent and severity as derived by PET polar maps in vivo against measurements derived from radiolabeled microspheres.

METHODS

In seven open-chest dogs, either the left anterior descending (n = 11) or left circumflex coronary artery (n = 13) were ligated sequentially from distal to proximal. After each occlusion, gated PET images were acquired with 13N-ammonia (20 mCi) while radiolabeled microspheres were administered into the left atrium. The transaxial PET images were reoriented into left ventricular short-axis cuts, including the apex, and polar maps were generated from circumferential activity profiles. PET polar maps were then compared with polar maps derived from microspheres after normal databases for 13N-ammonia and for microspheres were established. Nitrogen-13 or microsphere activities of less than 1.5 s.d. below the mean were defined as hypoperfused.

RESULTS

The extent (percent of left ventricular mass) and mean severity of the hypoperfused myocardium in the postmortem microsphere measurements ranged from 3% to 69% and 3% to 58%, respectively. The estimated extent by summed PET and by microspheres correlated by y = 4.95 + 0.95x (r = 0.91, s.e.e. = 0.085, p < 0.001) and mean severity by y = 5.52 + 0.87x (r = 0.85, s.e.e. = 0.101, p < 0.001). The extent and severity were similar for summed and gated PET studies.

CONCLUSION

The current study validated a polar map approach that provides accurate, quantitative assessment of the extent and severity of myocardial perfusion defects in vivo. Gating did not yield an improved correlation between PET and microsphere measurements. Thus, ungated PET images can be used to assess accurately the extent and severity of perfusion defects.

In vitro investigation of blood compatibility of Ti with oxide layers of rutile structure

Structure characteristics of titanium oxide layer on titanium matrix were investigated by Rutherford Backscattering Spectroscopy (RBS), Auger Electron Spectroscopy (AES) and X-ray diffraction. It has been identified that the titanium oxide layers had rutile structure. The blood compatibility of the titanium oxide layers of different thickness was studied by blood clotting time measurement. It was shown that as the thickness of the titanium oxide layers increased, blood compatibility of these layers was obviously improved.

Identification of a putative alternate sigma factor and characterization of a multicomponent regulatory cascade controlling the expression of Pseudomonas syringae pv. syringae Pss61 hrp and hrmA genes

The Pseudomonas syringae hrp and hrmA genes controlling pathogenicity and elicitation of the hypersensitive response and the avr genes controlling host range have been shown previously to be regulated by carbon, nitrogen, pH, osmolarity, and hypothetical plant factors. In P. syringae pv. syringae Pss61, inactivation of hrp complementation groups II and XIII reduced expression of a plasmid-borne hrmA'-lacZ fusion. The hrp regions II and XIII were cloned on separate plasmids and shown to enhance the activity of the hrmA promoter in Escherichia coli MC4100 transformants at least 100-fold. The nucleotide sequence of region XIII revealed two open reading frames (hrpR and hrpS) whose deduced products share homology with P. syringae pv. phaseolicola NPS3121 HrpS and are both related to the NtrC family of two-component signal transduction systems. HrpR and HrpS differ from most members of the protein family by lacking an amino-terminal domain which modulates the regulatory activity. A single open reading frame, hrpL, whose product shares homology with AlgU, a putative alternate sigma factor of P. aeruginosa, as well as with the related alternate sigma factors was identified within region II. Key domains are partially conserved. Inactivation of hrpS in Pss61 repressed expression of a plasmid-borne hrpL'-lacZ fusion carried by pYXPL1R, and transformation of MC4100(pYXPL1R) with a plasmid carrying hrpRS increased hrpL promoter activity at least 200-fold. Neither hrpS nor hrpR, when cloned on separate plasmids, activated the hrpL promoter activity individually. The expression of hrpL when directed by a lac promoter was sufficient to express a set of plasmid-borne hrmA'-, hrpJ'-, and hrpZ'-lacZ fusions independently of other hrp genes. The results indicate that hrpRS and hrpL are part of a regulatory cascade in which HrpR and HrpS activate expression of hrpL and HrpL, a putative sigma factor, induces expression of HrpL-responsive genes.

Somatic diversification and affinity maturation of IgM and IgG anti-DNA antibodies in murine lupus

Molecular events occurring during the process of generation of pathogenic immunoglobulin (Ig)G anti-DNA antibodies in systemic lupus erythematosus (SLE) were studied using a newly established method. We analyzed the Ig variable (V) region gene sequence and DNA-binding activity of IgM and IgG anti-DNA monoclonal antibodies (mAb) from individual SLE-prone (NZB x NZW) F1 mice. The first event appeared to be clonal selection and expansion of IgM anti-DNA clones, in which several clones had intraclonal V gene mutations. Although the number of mutations was small, the mutated IgM clones were associated with an increase in DNA-binding activity. The somatic mutations located in complementarity-determining regions (CDR) and in framework regions (FR) of V genes were apparently related to changes in DNA-binding activity. IgG anti-DNA clones that progressively increased in number with aging had numerous somatic mutations in the V region genes and there was a pair of clones which showed an intraclonal accumulation of mutations, in association with increase in the DNA-binding activity. All these findings show that somatic mutations associated with affinity maturation of the V region begin immediately before isotype-switching from IgM to IgG of the clones that have been selected and expanded, in an antigen-driven manner and/or by other forces. We propose that further accumulations of intraclonal somatic hypermutation, in association with selection and expansion of high affinity IgG clones, may lead to formation of highly pathogenic anti-DNA antibodies.

[Lysosomes in the regulation of hormone secretion in the pituitary-adrenal gland axis]

The morphology and morphometrics of the lysosomes and associated structures were studied in hyposecreting corticotrophs and the cells of adrenal cortex zona fasciculata of the rats. Hyposecretion of this two types of the cells in the pituitary-adrenal gland axis was induced by dexamethasone administration. The lysosomes and other hydrolydase-positive structures were identified with CMPase cytochemistry. Quantitative evaluation of the lysosomes, crinophagic and autophagic vacuoles was carried out on the micrographs with MOP-Videoplan system. The results indicated that while inhibited secretion of ACTH accompanied by the increase of the crinophagic and autophagic vacuoles in corticotrophs, inhibited secretion of corticosterone accompanied by the increase of the autophagic vacuoles containing the mitochondria, ER which were steroid-synthesizing apparatus in adrenal cortex cells. The findings in the present study suggested that lysosomal degradation mechanism play a significant role in the regulation of hormone secretion in pituitary-adrenal gland axis. In addition to affirming earlier data that lysosomes took part in the regulation of protein secretion by crinophagy, the main conclusion derived from the present study was that lysosomes also functioned in the regulation of steroid secretion. By the way of autophagy i.e. sequesting and degrading a part of the steroid-synthesizing apparatus, the lysosomes rendered a mechanism in steroid-secreting cells to involve to the regulation process of hormone secretion. This might be an important and general rule as the crinophagy be to the protein-secreting cells.

[Leydig cells--a normal cell model of cellular autophagy]

In the present study, we tried to estimate, in a semiquantitative way, the relative frequency of the autophagic activity in various cell types under physiological condition. The results indicated that the highest activity appeared to be in the Leydig cells of rat testes. Autophagosomes were frequently observed in electron microscope photographs of Leydig cells, which provide a good model to study the autophagocytosis in normal cells. The autophagic process in Leydig cells was observed with the electron microscope in preparations treated to show CMPase activity. The mode of formation of autophagosomes in Leydig cells can be divided into three steps. Step 1, flattened membranous elements expand to enclose a small cytoplasmic territory to form pre-autophagosome. Step 2, The double membrane profile of the pre-autophagosome then completely encloses the cytoplasmic territory to form early autophagosome in which structurally normal organelles are contained. Step 3, the transformation of an early autophagosome into a late one is accompanied by the loss of one of the two delimiting membranes, the partial disintegration of the enclosed content and simultaneous acquisition of acid phosphatase activity. The enzymatic reactivity is acquired following a close association with the lysosomes. The late autophagosome then reaches the cell surface and appear to exocytose their residual content.

[Lysosomes in the regulation of hormone secretion in endocrine cells]

Enzyme cytochemistry and immunocytochemistry were utilized to study the morphological alterations of the lysosomes and associated crinophagic and autophagic structures in the hypo-secreting pituitary gonadotrophin and Leydig cells induced by exogenous androgen. The lysosomes and autophagic vacuoles in the electron micrographs were quantitatively analysed. The morphological and quantitative data led to the following conclusions: 1) The hypo-secreting gonadotrophin showed an increase in the number of lysosomes and an enhancement of crinophagy. It demonstrated once again that the lysosomes in the protein and polypeptide hormone secreting cells play a role in the regulation of secretion process by means of the crinophagy. 2) The hypo-secreting Leydig cells showed an increase in the number of lysosomes and an enhancement of autophagic activity. This indicated that the lysosomes in the steroid hormone secreting cells also function in the regulation of hormone secretion but by means of autophagy which scavenge a part of steroid-producing apparatus and hormone. The autophagy might have similar effect in regulation of steroid secretion to the crinophagy in regulation of protein secretion.