Exploring the interaction of some N-benzyloxycarbonyl-L-phenyl alanyl-L-alanine ketones and bovine spleen cathepsin B by molecular modeling and binding free energy calculation

A semi-empirical method for estimation of binding free energy, recently proposed by Aqvist and coworkers, has been effectively tested in several protein-ligand binding cases. We have applied this linear interaction energy method to predict the binding of some N-benzyloxycarbonyl-L-phenyl alanyl-L-alanine ketones with bovine cathepsin B and computed the respective absolute binding constants from averages of molecular dynamics simulations. It is found that the computer simulation results agree well with available experimental data and make it possible to understand better the origin of tight binding and inhibitor specificity of cathepsin B.     

Fractal dimension in aspiration cytology smears of breast and cervical lesions

OBJECTIVE: To standardize the automated measurement of fractal dimension on cytologic smears and compare the fractal dimension of benign and malignant breast cells and cervical lesions on cytologic material to evaluate its role in the discrimination of benign from malignant cells. STUDY DESIGN: We randomly selected fine needle aspiration cytology smears of 42 cases of infiltrating duct carcinoma and 38 cases of fibroadenoma of the breast. Similarly, 16 cervical carcinoma and 20 normal cervical smears were selected for study. Ten cells were selected randomly from each case. Box counting of fractal dimension of malignant and benign cells was achieved with an image cytometer (Leica, Cambridge, England) using Quantimet 600 software (Leica). Then a well-spaced grid with multiple small boxes of a particular pixel length was superimposed on the cell. The dimension of the box was selected as 4, 8 and 16 pixels. With the help of a logical "AND" operation, we counted the number of boxes touching the peripheral margin of the cell nuclei. For each cell, the log-log graph of 1 per box size was plotted against the number of boxes touching the peripheral rim of the cell. The slope of each graph was identified using the least-squares method of regression analysis. RESULTS: The mean fractal dimension of malignant cells was 0.8536 +/- 0.1120 as compared to 0.8403 +/- 0.1115 in benign cell groups. The Mann-Whitney U test showed a significant difference in fractal dimension in these 2 groups (P = .05). The mean fractal dimension of malignant cells from the cervix was 0.8656 +/- 0.1499 as compared to 0.8315 +/- 0.1312 in benign cells. The Mann-Whitney U test showed a significant difference in fractal dimension in these 2 groups (P < .02). CONCLUSION: Fractal dimension may be a helpful adjunctive technique to discriminate between benign and malignant cells.     

Fractal dimension in endometrial carcinoma

OBJECTIVE: To mathematically assess in a pilot study, endometrial glandular margin irregularity in simple hyperplasia, complex atypical hyperplasia and well-differentiated endometrial carcinoma with the help of box counting of fractal dimension and to discriminate these lesions on the basis of box counting of fractal dimension of the gland. STUDY DESIGN: Ten cases each of endometrial simple hyperplasia (without atypia), complex hyperplasia with atypia and endometrial carcinoma (well-differentiated, endometrioid) were assessed in the study. Five fields at 20 x magnification from each case were randomly selected, and the glands were outlined with the help of a pointer. Using the box counting method, the fractal dimension of each case was measured. RESULTS: Mean fractal dimension in simple hyperplasia, complex atypical hyperplasia and endometrial carcinoma was, 0.899 +/- 0.13, 0.932 +/- 0.042 and 0.939 +/- 0.02, respectively. Statistical analysis showed that the fractal dimension of glands of simple hyperplasia were significantly different from that of complex atypical hyperplasia and endometrial carcinoma (P = .041 and .013, respectively, ANOVA). However, there was no significant difference in fractal dimension between glands of complex hyperplasia and of endometrial carcinoma (P = .659, ANOVA). CONCLUSION: This study provides mathematical (objective) assessment of the measurement of glandular margin irregularities in simple hyperplasia, complex atypical hyperplasia and endometrial carcinoma. Fractal dimension of gland margin may have diagnostic potential in the future.     

Uterine Msx-1 and Wnt4 signaling becomes aberrant in mice with the loss of leukemia inhibitory factor or Hoxa-10: evidence for a novel cytokine-homeobox-Wnt signaling in implantation

Successful implantation absolutely depends on the reciprocal interaction between the implantation-competent blastocyst and the receptive uterus. Expression and gene targeting studies have shown that leukemia inhibitory factor (LIF), a cytokine of the IL-6 family, and Hoxa-10, an abdominalB-like homeobox gene, are crucial to implantation and decidualization in mice. Using these mutant mice, we sought to determine the importance of Msx-1 (another homeobox gene formerly known as Hox-7.1) and of Wnt4 (a ligand of the Wnt family) signaling in implantation because of their reported functions during development. We observed that Msx-1, Wnt4, and a Wnt antagonist sFRP4 are differentially expressed in the mouse uterus during the periimplantation period, suggesting their role in implantation. In addition, we observed an aberrant uterine expression of Msx-1 and sFRP4 in Lif mutant mice, and of Wnt4 and sFRP4 in Hoxa-10 mutant mice, further reinforcing the importance of these signaling pathways in implantation. Collectively, the present results provide evidence for a novel cytokine-homeotic-Wnt signaling network in implantation.     

Poly(3-hydroxybutyrate) biosynthesis in the biofilm of Alcaligenes eutrophus, using glucose enzymatically released from pulp fiber sludge

Glucose, enzymatically released from pulp fiber sludge, was combined with inorganic salts and used as a growth medium for Alcaligenes eutrophus, a gram-negative strain producing poly(3-hydroxybutyrate) (PHB). By controlling the concentrations of the inorganic salts in the growth medium, almost 78% of the cell mass was converted to pure PHB. Efforts were made to find conditions for bacterial growth in the form of a biofilm on a cheap and reusable carrier. A number of positively charged carriers were tested, and the anion exchanger DEAE-Sephadex A-25 was chosen as a microcarrier for packed-bed biofilm cultures of A. eutrophus. Conditions for attachment, growth, and detachment were established. Biofilm formation on the microcarrier is strongly dependent on the ionic strength of the attachment medium. In order to achieve formation of the biofilm and its recovery from the microcarrier, the ionic strengths of the attachment and the detachment media were varied. Low ionic strength was tested for attachment, and high ionic strength was tested for detachment. Although biofilm formation in the packed-bed reactor is limited, the volumetric yield of cells based on the void volume of the packed bed is comparable with the batch culture yield.     

Bile acid amides derived from chiral amino alcohols: novel antimicrobials and antifungals

Cholic and deoxycholic acid amides 10-17 have been synthesised from (1R,2R)-1-phenyl-2-amino-1,3-propanediol 2, (1S,2S)-1-phenyl-2-amino-1,3-propanediol 4, (1R,2R)-1-para-nitrophenyl-2-amino-1,3-propanediol 3, (1S,2S)-1-para-nitrophenyl-2-amino-1,3-propanediol 5. Amide 12 derived from N-succinimidyl ester 9 of deoxycholic acid and (1R,2R)-1-phenyl-2-amino-1,3-propanediol 2, found to be active against Cryptococcus neoformans and the amide 17 obtained from N-succinimidyl ester 9 of deoxycholic acid and (1S,2S)-1-para-nitrophenyl-2-amino-1,3-propanediol 5, is found to be potent against various gram-positive bacteria.     

Mouse zinc transporter 1 gene provides an essential function during early embryonic development

The SLC30 family of cation diffusion transporters includes at least nine members in mammals, most of which have been documented to play a role in zinc transport. The founding member of this family, Znt1, was discovered by virtue of its ability to efflux zinc from cells and to protect them from zinc toxicity. However, its physiological functions remain unknown. To address this issue, mice with targeted knockout of the Znt1 gene were generated by homologous recombination in embryonic stem cells. Heterozygous Znt1 mice were viable. In contrast, homozygous Znt1 mice died in utero soon after implantation due to a catastrophic failure of embryonic development. Although extraembryonic membranes formed around these embryos, the embryo proper failed to undergo morphogenesis past the egg cylinder stage and was amorphous by d9 of pregnancy. Expression of the Znt1 gene was detected predominantly in trophoblasts and in the maternal deciduum during the postimplantation period (d5 to d8). The failure of homozygous Znt1 embryos to develop could not be rescued by manipulating maternal dietary zinc (either excess or deficiency) during pregnancy. However, embryos in Znt1 heterozygous females were approximately 3 times more likely to develop abnormally when exposed to maternal dietary zinc deficiency during later pregnancy than were those in wildtype females. These studies suggest that Znt1 serves an essential function of transporting maternal zinc into the embryonic environment during the egg cylinder stage of development, and further suggest that Znt1 plays a role in zinc homeostasis in adult mice.     

Synthesis and structure-activity relationship studies of cinnamic acid-based novel thiazolidinedione antihyperglycemic agents

A number of 2,4-thiazolidinedione derivatives of -phenyl substituted cinnamic acid were synthesized and studied for their PPAR agonist activity. The E-isomer of cinnamic acid, 11, showed moderate PPAR transactivation. The corresponding Z-isomer, 23, and double bond reduced derivative, 15, were found to be much less potent. Although the E-isomer showed a moderate PPAR gamma transactivation, it demonstrated a strong glucose-lowering effect in a genetic rodent model of diabetes. Results of pharmacokinetic, metabolism and permeability studies are consistent with 11 being an active prodrug with an active metabolite, 14, that has similar glucose lowering and PPAR gamma agonist properties.     

Terminal uridine nick end labelling and mitosis in breast carcinoma. Correlation with tumor grade and p53 overexpression

OBJECTIVE: To study the relationship of cell death and proliferation to histologic grade and p53 expression in invasive carcinoma of the breast. STUDY DESIGN: A total of 31 cases of infiltrating duct carcinoma of the breast were randomly selected. The terminal deoxynucleotidyl-transferase-mediated dUTP nick end labelling (TUNEL) reaction and p53 immunostaining were performed on representative paraffin-embedded tissue sections. Mitotic and apoptotic indices (MI and AI) were also measured on hematoxylin-eosin-stained sections. Histologic grade of infiltrating duct carcinoma was performed with the help of the Nottingham modification of the Bloom-Richardson system. Tumor grade and p53 overexpression were correlated with MI, AI and AI detected by TUNEL. RESULTS: There were a total of 31 infiltrating duct carcinomas of the breast, of which 13 cases were grade 1 and nine cases each were grade 2 and 3. Cells with positive TUNEL showed a strong brown nuclear positivity. TUNEL showed positivity from the periphery of the nuclear margin to the central portion. AI detected by TUNEL did not correlate with tumor grade (ANOVA, P > .05). MI was significant only in grade 1 versus grade 3 and 2 versus grade 3 carcinomas (ANOVA, P < .01). The morphologic apoptotic index was significant only in grade 1 versus grade 3 carcinomas. Nine cases showed p53 overexpression, and the rest of the cases were negative for p53 immunostaining. MI, AI and TUNEL were not significantly different in p53-negative and -positive groups. Pearson's correlation coefficient showed that AI and MI were significantly related, but there was no significant relation between AI detected by TUNEL and MI. CONCLUSION: MI is still more useful than AI or AI detected by TUNEL in differentiating various grades of carcinoma of the breast.