Highly efficient and versatile synthesis of libraries of constrained beta-strand mimetics

The general approach of using a bicyclic template to produce inhibitors of the protease superfamily of enzymes has been investigated. The Diels Alder cycloaddition reaction on solid support has been found to be highly efficient for the synthesis of libraries of compounds that mimic the beta-strand secondary structure of proteins. Several potent and selective inhibitors of proteases have been discovered.

[Alteration in regional blood flow in minipigs' femur under inadequate decompression studied by isotopes washout method]

We studied the alteration in regional blood flow in minipigs' femur under inadequate decompression after hyperbaric air exposure. The animals were placed in the hyperbaric chamber and exposed to the pressure of 0.5 MPa for 1.5 h, which was reduced to atmosphere at an ascent rate of 0.03-0.04 MPa/min. Regional blood flow in the femur was measured by the isotopes washout method of inhaling 133Xe. The radioactivity was monitored by a multifunctional blood flowmeter interfaced to a minicomputer. Before exposure, the values of average blood flow (F) of femur on the left and right were 15.4 +/- 1.8 and 16.9 +/- 2.0 ml/100 g.min respectively. The values of blood flow (f1) of hematopoietic marrow were 19.1 +/- 2.0 and 21.3 +/- 2.0 ml/100 g.min (n = 7). After inadequate decompression, F values were reduced to 10.3 +/- 1.8 and 11.1 +/- 1.6 ml/100 g.min and f1 values reduced to 13.9 +/- 1.4 and 13.8 +/- 1.0 ml/100 g.min (n = 7), which were obviously lower than those before exposure (P < 0.05). This experiment showed that significant reduction in blood flow in the femur region occurred under inadequate decompression after the exposure of minipigs hyperbaric environment, suggesting that ischemia is a causative factor of osteonecrosis.

Adenine auxotrophic heterozygosity in Candida krusei

Candida krusei CK 18 carries heterozygosity for a recessive adenine biosynthesis allele, as it can be induced by UV irradiation to form adenine mutants at high frequency. The resultant mutants were characterized with the phenotype of red colony and residual growth on minimal media. The majority of the descendant prototrophic segregates were capable of continuous segregation to adenine mutants, suggesting gene conversion as one possible mechanism for the occurrence of the adenine auxotroph in the isolate.

UV irradiation-induced apoptosis leads to activation of a 36-kDa myelin basic protein kinase in HL-60 cells

UV irradiation induces apoptosis (or programmed cell death) in HL-60 promyelocytic leukemia cells within 3 h. UV-induced apoptosis is accompanied by activation of a 36-kDa myelin basic protein kinase (p36 MBP kinase). This kinase is also activated by okadaic acid and retinoic acid-induced apoptosis. Irrespective of the inducing agent, p36 MBP kinase activation is restricted to the subpopulation of cells actually undergoing apoptosis. Activation of p36 MBP kinase occurs in enucleated cytoplasts, indicating no requirement for a nucleus or fragmented DNA in signaling. We also demonstrate the activation of p36 kinase in tumor necrosis factor-alpha- and serum starvation-induced cell death using the human prostatic tumor cell line LNCap and NIH 3T3 fibroblasts, respectively. We postulate that p36 MBP kinase is a common component in diverse signaling pathways leading to apoptosis.

The transcription activator steroidogenic factor-1 is preferentially expressed in the human pituitary gonadotroph

Steroidogenic factor-1 (SF-1), also known as adrenal-4-binding protein, is a transcription factor that is important for the differentiation of steroidogenic tissues. We investigated whether SF-1 is expressed in specific hormone-producing cell types in the human pituitary and its adenomas. Pituitary adenomas (n = 35) were collected at the time of surgery, and normal adenohypophyses were obtained from autopsies; 3 corticotroph adenomas were excluded because pit-1 messenger ribonucleic acid (mRNA) expression indicated contamination by nontumorous elements. Expression of SF-1 mRNA was determined by reverse transcription-PCR. SF-1 protein was localized with immunocytochemistry. By reverse transcription-PCR, SF-1 mRNA was found in the nontumorous pituitary and in pituitary adenomas expressing gonadotropins. All 8 gonadotroph adenomas had a strong signal for SF-1. SF-1 mRNA was also detected in 2 of 3 corticotroph adenomas, 2 of 13 somatotroph/mammosomatotroph adenomas, 1 of 6 lactotroph adenomas, and 2 silent subtype 3 adenomas; however, in most of the positive tumors there was also positivity for FSH beta and/or LH beta mRNA, suggesting that contaminating nontumorous gonadotrophs may be the source of SF-1 mRNA signal. SF-1 protein was localized by immunocytochemistry in the nuclei of scattered cells of the nontumorous adenohypophysis that were shown to be gonadotrophs with double immunostaining and in gonadotroph adenomas; nuclear staining was not found in other adenoma types, except in areas shown to contain trapped nontumorous tissue. We conclude that SF-1 expression correlates with the expression of gonadotropins. These findings implicate SF-1 as a cell-specific transcription factor that may regulate gonadotroph differentiation in the pituitary.

Expression of steroidogenic factor-1 (SF-1) mRNA and protein in the human placenta

Steroidogenic factor-1 (SF-1), also known as adrenal-4-binding protein (Ad4BP), is a recently-described transcription factor, which has been shown to be important for the differentiation of steroidogenic tissues. In addition, SF-1 has been implicated in regulating the glycoprotein hormone alpha-subunit gene in a pituitary gonadotroph cell line. Considering that the human placenta produces both steroids and human chorionic gonadotrophin (HCG), we studied the expression of SF-1 in this tissue. Human first trimester and term placentas were collected at the time of therapeutic abortion and birth respectively. Messenger RNA was extracted, reverse transcribed, and used for polymerase chain reaction (PCR) amplification with primers specific for the human SF-1 cDNA sequence. A band of the expected size was obtained from both first and third trimester samples, indicating that SF-1 expression in the human placenta starts early in pregnancy and is maintained until birth. In addition to normal placental samples, JEG3 and JAR choriocarcinoma cells were also analysed and found to express SF-1 mRNA. The identity of the amplified products was confirmed by diagnostic restriction digest and Southern hybridization. SF-1 protein was localized mainly to the nuclei of the cyto- and syncytiotrophoblast and to some mesenchymal villous nuclei by immunocytochemistry using a specific antibody. We conclude that SF-1 is expressed in human first trimester and term placenta, where it could be implicated in the regulation of HCG production, in steroidogenesis, or both.

Exploration for drug therapy in endometrial carcinoma

OBJECTIVE

To explore the therapeutic effect of three drugs, i.e., hydroxyprogesterone caproate (HPC), Tamoxifen (TMX) and Aminoglutethimide (AG), in the treatment of endometrial carcinoma.

METHODS

The patients were collected by double-blind method and classified into 6 groups (3 groups used single drug and 3 groups used combined drugs) at random. The patient was given assigned drug therapy for 10 days according to her group after being admitted to the hospital. Operations were performed 7-10 days after drug therapy. Plasma FSH, LH, E2 and P were measured by standard radioimmunoassay of WHO. ER and PR in cancer tissues were examined by enzyme linked histochemistry. Cancer tissues obtained before and after drug therapy were examined pathologically.

RESULTS

The values of FSH, LH and E2 decreased and that of P increased after single drug therapy in the group treated with HPC; and the values of FSH, LH, E2 and P all decreased in the groups treated with TMX and AG respectively (P < 0.05). The values of FSH, LH and E2 decreased to different extent in the groups treated with combined drugs. The changes of FSH and E2 are remarkable (P < 0.05). The value of P increased a little with no statistical difference (P > 0.05). PR and ER usually increased after treatment with TMX, but decreased with HPC or AG, or combined drugs. The pathological changes indicate that the tumors responded to all of the three drugs. The response to TMX was most significant, following which was HPC.

CONCLUSIONS

HPC and TMX are two drugs proved to be useful in endometrial carcinoma. AG also can be used to treat endometrial carcinoma. It adds a new drug to the drug therapy for endometrial carcinoma.

Distal 8p deletion (8)(p23.1): an easily missed chromosomal abnormality that may be associated with congenital heart defect and mental retardation

We describe the clinical manifestations and molecular cytogenetic analyses of three patients with a similar distal deletion of chromosome 8. Each child had mild developmental delay and subtle minor anomalies. Two had cardiac anomalies but no other major congenital anomalies were present. High resolution G and R banding showed in all three patients del(8)(p23.1), but the breakpoint in case 1 was distal to 8p23.1, in case 2 was in the middle of 8p23.1, and in case 3 proximal to 8p23.1. Fluorescence in situ hybridization (FISH) studies with a chromosome 8 paint probe confirmed that no other rearrangement had occurred. FISH with a chromosome 8-specific telomere probe indicated that two patients had terminal deletions. Chromosome analysis of the parents of case 1 and mother of case 2 were normal; the remaining parents were not available for study. Thirteen individual patients including the three in this study, and three relatives in one family with del(8)(p23.1), have been reported in the past 5 years. Major congenital anomalies, especially congenital heart defects, are most often associated with a breakpoint proximal to 8p23.1. Three patients were found within a 3-year period in this study and five cases were found within 4 years by another group, indicating that distal 8p deletion might be a relatively common chromosomal abnormality. This small deletion is easily overlooked (i.e., cases 1 and 2 were reported as normal at amniocentesis) and can be associated with few or no major congenital anomalies.

Nuclear magnetic resonance chemical shift: comparison of estimated secondary structures in peptides by nuclear magnetic resonance and circular dichroism

Traditionally, CD has been used extensively for peptides in secondary structure analysis. In recent years, NMR chemical shifts and nuclear Overhauser enhancements have been widely used in conjunction with CD to assess the secondary structures of peptides and proteins; however, there are many instances where the estimation of secondary structure contents differs significantly between the two methods. In order to elucidate the perceived differences between the two methods, secondary structure estimations by CD and 1H NMR chemical shifts were compared for over 50 peptides. The linear peptides investigated were largely unstructured, approximately 15-50 residues in size, and lacked stable tertiary conformation. These peptides were studied in different solvent systems including water, alcohol-water, micelles and urea. A strong correlation exists for secondary structure assessment by CD and NMR chemical shifts; however, an interesting trend of higher estimation of helical contents by NMR was observed for peptide fragments from globular proteins studied in water. This may be a result of associative properties of these peptides in water. Additionally, a new method of quantitating secondary structure contents based on 1H NMR chemical shifts is reported.

A disc plate assay for characterization of the effect of interaction between polyenes and azoles on growth of Candida albicans CA12

A simple, reproducible and efficient assay was described for visual demonstration that triazole fluconazole interfered with the anti-Candida albicans activity of polyene amphotericin B. The assay also indicated the existence of more than one antifungal mechanism involving imidazole ketoconazole.

[Antidepressant active constituents in the roots of Morinda officinalis How]

Five compounds having antidepressant activities have been isolated from the roots of Morinda officinalis, a Chinese traditional Yang-tonic drug. These compounds were identified as succinic acid (1), nystose (2), 1F-fructofuranosylnystose (3), inulin-type hexasaccharide (4) and heptasaccharide (5) by chemical and spectroscopic methods. All of the compounds are isolated from the species of genus Morinda for the first time.

[Application of the thoraco-umbilical flap in emergent repair of large defect of limbs]

We have repaired larger detect of limbs after emergent debridement using the thoraco-umbilical flap on 13 cases, 6 of which were vascular island flaps, 7 were free flaps. The size of the flaps was 10 cm x 26 cm to 12 cm x 42 cm. All the flaps survived completely. The advantages of the flap are: (1) the pedicle of the flap is long and has a large diameter, (2) the flap can be made quite long so as to cover the whole ulna or tibia, (3) the flap can be used to repair bony defect by carrying a rib as an osteocutaneous flap.

[Central inhibition action of Valeriana jatamansii Jones]

The use of water extract (ip or ig) of Valeriana jatamansii together with pentobarbital sodium can enhance sedative and hypnotic effect in mice, inhibit the spontaneous activity in mice, and antagonize convulsive action induced by thiosemicarbazide (TSZ). Although ineffective on the convulsion induced by picrotoxin (PT), it can prolong the latent period of convulsion induced by PT in mice. The number of writhings in mice can be reduced after ip or ig water extract.

Hevein: NMR assignment and assessment of solution-state folding for the agglutinin-toxin motif

The first high-resolution solution-state structure of a member of the toxin-agglutinin folding motif with the WGA disulfide linkage is presented. The 1H NMR spectrum of hevein has been 100% assigned from residue 2 through residue 43, the C-terminus, using two-dimensional correlation and NOE spectroscopy. During the course of the NOESY analysis, the three-dimensional structural features of hevein were derived, using nonstereospecific distance constraints (with tight bounds) for XPLOR simulated annealing followed by unconstrained relaxation in the CHARMm force field, at two levels of long-range constraint density. In addition, a large number of low-bound-only constraints, corresponding to unobserved NOE's, were used in both refinements. The first structure elucidation employed a total of 180 distance constraints (60 of which were medium or long range, i/i+n with n < or = 2). The second refinement employed 244 (101 medium or long range) constraints: some conformation-insensitive intraresidue constraints were deleted, two misassigned long-range constraints were corrected, and 41 new i/i+n (n > or = 2) constraints were added. The average bounds precisions of the two refinements were comparable (+/- 0.44 A) and significantly tighter than those that result when a universal low bound corresponding to the sum of the van der Waals radii was used. (The more conservative treatment of NOE's gave the same final structure but required a higher constraint density before assignment errors would stand out during the refinement.) Constraint density also has a significant influence on convergence and accuracy using tight constraints. The study demonstrates that convergence within an ensemble of solution structures is not a dependable criterion for either the accuracy or precision of the derived structure. The best fitting conformers from the refinement at the higher constraint density bear a greater similarity to the solid-state structure of the domains of wheat germ agglutinin (0.95 A rmsd over residues 2-32) than to the recently reported 2.8-A X-ray structure of hevein (1.25 A rmsd over residues 2-32, 2.83 A rmsd over residues 2-42). The consensus conformer from the solution data is defined to a backbone rmsd of < 0.6 A over the full sequence for which NMR data could be collected.(ABSTRACT TRUNCATED AT 400 WORDS)

Peptide/protein structure analysis using the chemical shift index method: upfield alpha-CH values reveal dynamic helices and alpha L sites

The alpha-CH shifts observed by 1H NMR for medium-sized peptides and for an unusual small protein, herein, which has a high density of alpha L conformations within its 43 residue length, reveal that the recently introduced chemical shift index (CSI) analysis places short dynamic helices (alpha R) and alpha L residues in the same category as stable helices. The method appears to be a promising addition to the arsenal of methods for peptide structure analysis and is clearly not limited to rigid protein systems.