The prediction of late rectal complications following the treatment of uterine cervical cancer by high-dose-rate brachytherapy

PURPOSE

This study aimed to correlate patient, treatment, and dosimetric factors with the risk of late rectal sequelae in patients with uterine cervical cancer treated with external beam radiation therapy (EBRT) and high dose rate intracavitary brachytherapy (HDRICB).

METHODS AND MATERIALS

From September 1992 to December 1995, a total of 128 patients with uterine cervical cancer, who were treated and survived more than 12 months, were evaluated. After EBRT with 40-44 Gy/20-22 Fr/4-5 weeks to the whole pelvis, the dose was boosted up to 54-58 Gy with central shielding for patients with bilateral parametria of Stage IIb or greater. HDRICB consisted of three to four insertions at doses of 5-7.2 Gy (to Point A) at intervals of 1 week. Patient and treatment factors were analyzed using logistic regression analysis and the cumulative rectal biologic equivalent dose (CRBED) was calculated.

RESULTS

After 30-75 months of follow-up (median, 43 months), 38 patients (29.7%) had late rectal sequelae. Patients who had Stage IIb-IVa disease, cumulative rectal dose (external RT + total ICRU rectal dose) greeater than 65 Gy, or age greater than 70 years had a high risk of developing late rectal sequelae. When 110 Gy was used as the cut-off value, 19.6% (10 of 51) of patients whose CRBED was less than 110 Gy had rectal complications, while 36.4% (28/77) of patients whose CRBED was greater than 110 Gy developed rectal complications.

CONCLUSION

Risk factors of late rectal complications were advanced stage, age greater than 70 years, and cumulative rectal dose of greater than 65 Gy.

Oxygen-glucose deprivation induces inducible nitric oxide synthase and nitrotyrosine expression in cerebral endothelial cells

BACKGROUND AND PURPOSE

The cerebral endothelial cells (ECs) are a primary target of hypoxic or ischemic brain insults. EC damage may contribute to postischemic secondary injury. Massive production of NO after inducible NO synthase (iNOS) expression has been implicated in cell death. This study aimed to characterize bovine cerebral EC death in relation to iNOS expression after oxygen-glucose deprivation (OGD) in vitro.

METHODS

OGD in bovine cerebral ECs in culture was induced by deleting glucose in the medium and by incubating the cells in a temperature-controlled anaerobic chamber. The extent of cell death was assessed by trypan blue exclusion, MTT assay, and LDH release. ELISA, gel electrophoresis, and staining by terminal deoxynucleotidyl transferase-mediated dUTP nick end-labeling were used to examine DNA fragmentation. The expression of iNOS mRNA and protein was detected by reverse transcription-polymerase chain reaction and Western blotting, respectively. Nitrotyrosine expression was confirmed with Western blot analysis and immunostaining.

RESULTS

Bovine cerebral EC death was dependent on the duration of OGD and showed selected biochemical, morphological, and pharmacological features suggestive of apoptosis. OGD also induced the expression of iNOS mRNA and protein in bovine cerebral ECs. Increased expression of nitrotyrosine, the product formed by peroxynitrite reaction with proteins, was also detected after OGD. The involvement of iNOS in EC death was suggested by partial reduction of cell death by NO synthase inhibitors, including L-N(G)-(1-iminoethyl)ornithine and nitro-L-arginine, and an NO scavenger, the Fe(2+)-N-methyl-D-glucamine dithiocarbamate complex.

CONCLUSIONS

OGD-induced bovine cerebral EC death involves an apoptotic process. Induction of iNOS with subsequent peroxynitrite formation may contribute to bovine cerebral EC death caused by OGD.

Automated gas chromatography with cryogenic/sorbent trap for the measurement of volatile organic compounds in the atmosphere

An automated gas chromatographic system was constructed to easily adapt either the cryogenic trap or chemical sorbent trap for preconcentrating ambient levels of volatile organic compounds. Remarkable similarity in chromatograms from C3 to C10 was found between these two enrichment methods, except that the sorbent trap did not quantitatively trap the C2-hydrocarbons. In contrast to cryogenic trapping, the chromatographic conditions for more volatile compounds were substantially improved using the sorbent trap. Water interference on the porous-layer open tubular column was also better managed using the sorbent trap for the continuous analysis of humid room air. The similarity in peak profiles between the GC-flame ionization detection (FID) and a commercial GC-MS system, regardless of concentration levels, facilitated compound identification on the FID chromatograms based on a field mission involving analysis of 106 air samples.

An improved alkaline lysis method for minipreparation of plasmid DNA

This study is to improve the digestion pattern of miniprepped plasmid analyzed on gel. Frequently, some ambiguous DNA bands, which are suspected to be denatured DNA molecules, appear during electrophoresis of enzyme digested miniprepped plasmids. By employing Southern hybridization of two identical gels, one had been treated with denaturation-neutralization step and another without such treatment, we confirmed that many of these ambiguous DNA bands were single-stranded (SS) DNA molecules. The presence of SS DNA was due to the use of excess amount of NaOH during plasmid DNA purification with the conventional alkaline lysis method. We, therefore, modified the procedure and recommend that a half amount of NaOH (0.1N instead of 0.2N) should be used when isolating small quantity of plasmid DNA with the method.

Focal organizing pneumonia mimicking small peripheral lung adenocarcinoma on CT scans

The present report of four cases highlights the potential for focal organizing pneumonia (FOP) to masquerade as a small peripheral lung adenocarcinoma on CT scans. Both entities may present the CT appearance of a peripheral spiculated lung nodule, often with an air bronchogram. A history suggestive of an infectious aetiology and the presence of other foci of inflammatory change on CT scan may be helpful clues to the diagnosis of FOP. Because FOP is comparatively rare, surgical excision will usually be required to exclude malignancy. In some cases, however, particularly after a negative percutaneous biopsy, conservative management with a follow-up CT scan at 3-4 weeks may be an alternative to immediate surgical intervention.

A conserved retinoic acid responsive element in the murine Hoxb-1 gene is required for expression in the developing gut

The murine Hoxb-1 gene contains a homeobox sequence and is expressed in a spatiotemporal specific pattern in neuroectoderm, mesoderm and gut endoderm during development. We previously identified a conserved retinoic acid (RA)-inducible enhancer, named the RAIDR5, which contains a DR5 RARE; this RAIDR5 enhancer is located 3′ of the Hoxb-1-coding region in both the mouse and chick. In the F9 murine teratocarcinoma cell line, this DR5 RARE is required for the RA response of the Hoxb-1 gene, suggesting a functional role of the DR5 RARE in Hoxb-1 gene expression during embryogenesis. From the analysis of Hoxb-1/lacZ reporter genes in transgenic mice, we have shown that a wild-type (WT) transgene with 15 kb of Hoxb-1 genomic DNA, including this Hoxb-1 3′ RAIDR5, is expressed in the same tissues and at the same times as the endogenous Hoxb-1 gene. However, a transgene construct with point mutations in the DR5 RARE (DR5mu) was not expressed in the developing foregut, which gives rise to organs such as the esophagus, lung, stomach, liver and pancreas. Like the wild-type transgene, this DR5 RARE mutated transgene was expressed in rhombomere 4 in 9.5 day postcoitum (d.p.c.) embryos. Similarly, transgene staining in the foregut of animals carrying a deletion of the entire Hox-b1 RAIDR5 enhancer (3′-del) was greatly reduced relative to that seen with the WT transgene. We also demonstrated that expression of the WT transgene in the gut increases in response to exogenous RA, resulting in anterior expansion of the expression in the gut. These observations that the Hoxb-1 gene is expressed in the developing gut and that this expression is regulated through a DR5 RARE strongly suggest a role for Hoxb-1 in the anteroposterior axis patterning of the gut and a critical role for endogenous retinoids in early gut development.

Axillary lymph node calcification due to metastatic papillary carcinoma

A case is presented in which calcification in an axillary lymph node seen on a screening mammogram was the presenting feature of metastatic papillary carcinoma, presumed to be of thyroid origin. The differential diagnosis of axillary lymph node calcification seen on mammography is reviewed.

Early stage nasopharyngeal carcinoma: radiotherapy dose and time factors in tumor control

OBJECTIVE

To evaluate radiotherapy dose and length of treatment in the control of early stage nasopharyngeal carcinoma (NPC) treated with a combination of external radiotherapy and brachytherapy,

MATERIALS & METHODS

We reviewed the records of 133 patients with early stage nasopharyngeal carcinoma (stage I or II, AJC/UICC staging system) who received definitive radiotherapy in Chang Gung Memorial Hospital from 1979 to 1991. The median follow-up time was 7.1 years with a minimum of 2 years. All patients were treated with megavoltage external radiotherapy to the nasopharynx area (63-72 Gy) followed by high dose rate intracavitary brachytherapy (5-16.5 Gy in one to three fractions, spaced 1-2 weeks apart). The median total dose and time of irradiation was 75 Gy (69.8-81.4 Gy) and 11.6 weeks (7.8-20 weeks) respectively. Survival analysis was used to examine the effect of several variables on prognosis.

RESULTS

The 5-year rates were 86.4% for local control, 84.7% for disease free survival, 88.5% for actuarial survival and 84.2% for overall survival. The treatment group (combination of time and dose of irradiation) was the most important prognostic factor according to Cox's proportional hazard model. Patients receiving radiation at a total dose of < or = 75 Gy completed in < 12 weeks showed the best prognosis.

CONCLUSION

Treatment time and total treatment dose are both important factors in treating early stage NPC. Decreasing the total radiation time to < 12 weeks and not exceeding a radiation dose of 75 Gy gave the best results.

Bilateral choroidal metastases as the initial presentation of a small breast carcinoma: a case report

Most ocular tumors metastasize from systemic origins in breast carcinoma in females, and bronchial carcinoma in males. Here, we report a case of choroidal carcinoma metastasis from the breast with visual problems being the only initial manifestations. In this case, both eyes were involved at almost the same time, with initial manifestation of blurred vision which progressed to complete visual loss. At first, the patient was diagnosed with malignant melanoma, and enucleation of the right eye was performed in another hospital. However, the tumor had already metastasized rapidly to numerous organs, including the lungs, brain and bone, although it had not affected the liver. Clinical presentations were, therefore, not compatible with those of malignant melanoma, which has usually been reported to metastasize to the liver. Persistent hypercalcemia and raised carcinoembryonic antigen (CEA) concentrations prompted investigations into the possibility of systemic malignancy. A very small breast nodule was finally located by thorough physical examination, and a lumpectomy was performed. A detailed review of the histopathology showed the tumors from the breast and the right eye to have the same origin. Simultaneous bilateral choroidal metastases from other malignancies is not uncommon; however, it is quite rare for breast carcinoma to present with visual problems as a first manifestation. Detailed history taking and physical examination are therefore essential when searching for a primary tumor, so that appropriate therapy can be given earlier.

An evolutionary conserved element is essential for somite and adjacent mesenchymal expression of the Hoxa1 gene

The murine Hoxa1 gene is a member of the vertebrate Hox complex and plays a role in defining the body plan during development. At day 8.0-9.0 post coitus, Hoxa1 transcripts are detected extensively throughout the embryo in the neural tube, adjacent mesenchyme, paraxial mesoderm, somites and gut epithelium; expression extends from the most caudal region of the embryo to the rhombomere 3/4 border. This spatiotemporal expression of Hoxa1 mRNA is critical for normal embryonic development. We have previously identified a 10 bp element, called CE2, which is located approximately 3 kilobases 3' of the Hoxa1 coding region in the RAIDR5 enhancer, and which binds to an approximately 170 kd protein in retinoic acid treated P19 embryonal carcinoma cells. CE2 elements were also identified 3' of the murine Hoxb1 gene, the chicken Hoxb1 gene and the human Hoxa1 gene. To examine the role of this CE2 element in regulating Hoxa1 expression in vivo, transgenic mice were generated which express a Hoxa1 beta-galactosidase reporter gene that contains a mutation in the CE2 element. Relative to transgenic mice bearing a wild type CE2 element, the mutant CE2 construct recapitulated rhombomeric, neural, and gut epithelium expression but failed to show beta-galactosidase expression in somites and adjacent mesenchymal tissue. Gel shift analysis showed that binding activity similar to that detected in extracts prepared from retinoic acid treated P19 cells was present in nuclear extracts prepared from day 9.0 embryos. However, an additional binding complex not detected in P19 cells was also observed. These results indicate that in transgenic animals, the evolutionary conserved CE2 element is a somite and adjacent mesenchymal enhancer of Hoxa1 expression.

Does conformational free energy distinguish loop conformations in proteins?

Limitations in protein homology modeling often arise from the inability to adequately model loops. In this paper we focus on the selection of loop conformations. We present a complete computational treatment that allows the screening of loop conformations to identify those that best fit a molecular model. The stability of a loop in a protein is evaluated via computations of conformational free energies in solution, i.e., the free energy difference between the reference structure and the modeled one. A thermodynamic cycle is used for calculation of the conformational free energy, in which the total free energy of the reference state (i.e., gas phase) is the CHARMm potential energy. The electrostatic contribution of the solvation free energy is obtained from solving the finite-difference Poisson-Boltzmann equation. The nonpolar contribution is based on a surface area-based expression. We applied this computational scheme to a simple but well-characterized system, the antibody hypervariable loop (complementarity-determining region, CDR). Instead of creating loop conformations, we generated a database of loops extracted from high-resolution crystal structures of proteins, which display geometrical similarities with antibody CDRs. We inserted loops from our database into a framework of an antibody; then we calculated the conformational free energies of each loop. Results show that we successfully identified loops with a "reference-like" CDR geometry, with the lowest conformational free energy in gas phase only. Surprisingly, the solvation energy term plays a confusing role, sometimes discriminating "reference-like" CDR geometry and many times allowing "non-reference-like" conformations to have the lowest conformational free energies (for short loops). Most "reference-like" loop conformations are separated from others by a gap in the gas phase conformational free energy scale. Naturally, loops from antibody molecules are found to be the best models for long CDRs (> or = 6 residues), mainly because of a better packing of backbone atoms into the framework of the antibody model.

A robust sequential detection algorithm for cardiac arrhythmia classification

In [1] qnd [2] Thakor et al. describe a sequential probability ratio test (SPRT) based on threshold crossing intervals (TCI) for the discrimination of ventricular fibrillation (VF) from ventricular tachycardia (VT). However, in applying their algorithm to data from the MIT-BIH malignant arrhythmia database, we observed some overlap in the distributions of TCI for VF and VT resulting in 16% overall error rate for the discrimination. In this communication, we describe a modified SPRT algorithm, using a new feature dubbed blanking variability (BV) as the basis for discrimination. Using the MIT-BIH database, the preliminary results showed that the proposed method decreases the overall error rate to 5%.

Evidence for mu1-opioid receptor involvement in fentanyl-mediated respiratory depression

Several fentanyl analogs (Bagley et al., 1989, J. Med. Chem. 32, 663) were compared to fentanyl and morphine for their effects on respiratory depression as determined by arterial blood gas (pH, pCO2 and pO2) measurements. Fentanyl (0.1 mg/kg), morphine (10 mg/kg), #16 (1-phenethyl-4-[N-(pyridin-2-yl)-N-(methoxymethylcarbonyl)amino] piperidine, 1 mg/kg), #17 (1-phenethyl-4-[N-(pyridin-2-yl) -N-(2-furoyl)amino]piperidine, 0.5 mg/kg) and #29 (1-phenethyl-4-[N- (pyrimidin-2-yl)-N-(methoxy-methylcarbonyl) amino]piperidine, 10 mg/kg) produced significant respiratory depression in rats. Pretreatment with the mu1-opioid receptor selective antagonist, naloxonazine (10 mg/kg), blocked the respiratory effect of fentanyl and its analogs, but not that of morphine. The results suggest that the mu1-opioid receptor plays an important role in the respiratory effects of fentanyl and its analogs. Hence, the mechanism of fentanyl-induced respiratory depression appears to be distinct from that produced by morphine. The most likely explanation for this difference is the possible contribution of muscle rigidity and catalepsy to the observed changes in blood gas parameters caused by the fentanyl analogs, while the respiratory depression of morphine, measured by these same parameters, appears to be independent of its effect on muscle rigidity.

Endoderm differentiation in vitro identifies a transitional period for endoderm ontogeny in the sea urchin embryo

The vegetal plate of the sea urchin embryo is specified during early cleavage divisions of the embryo as shown by the classical experiments of Horstadius (reviewed in "Experimental Embryology of Echinoderms," 1973, Clarendon, Oxford). Not until gastrulation, though, do the cells within this territory differentiate into their characteristic cell types. Vegetal plate descendents comprise the coelomic epithelium, circumesophageal muscle, basal cells, pigment cells, and endodermal epithelium. We report here that cells of the endodermal lineage acquire the ability to differentiate autonomously several hours prior to gastrulation, between the late blastula and early mesenchyme blastula stages. Cells dissociated from whole embryos after the late blastula stage have the ability to differentiate in vitro, independent of cell contacts and of the embryonic environment. In contrast, preendoderm cells removed from the embryo prior to the late blastula stage show no ability to differentiate when cultured in vitro even though cells of other lineages, e.g., ectoderm and skeletogenic mesenchyme, show morphological and molecular differentiation in these same cultures. We have used the expression of the endoderm-specific gene products Endo 1 and LvN1.2, detected by RNase protection assays and by in situ immunolabeling, to quantify endoderm differentiation independent of embryonic or cellular morphology. These studies define a transitional period in the ontogeny of the endoderm, from cells reliant on interactions to promote fate specification and organization of territories to later events involved in morphogenesis that result from cell-type-specific gene expression.

The hyperphagic effect of 3 alpha-hydroxylated pregnane steroids in male rats

Like benzodiazepines receptor (BDZR) ligands, 3 alpha-hydroxylated, 5 alpha, or 5 beta pregnane steroids are sedative, anticonvulsant, and anxiolytic. BDZR ligands also modulate the feeding response. Therefore, in this study we have investigated the effects of four 3 alpha-hydroxylated pregnane steroids-Pregnanolone (3 alpha-hydroxy-5 beta-pregnan-20-one), allopregnanolone (3 alpha-hydroxy-5 alpha-pregnan-20-one), alphaxalone (3 alpha-hydroxy-5 alpha-pregnan-11,20-dione), and 5 beta-pregnanediol (5 beta-pregnan-3 alpha,20 alpha-diol) on food intake. In non-food deprived male rats, all four steroids increased the consumption of a palatable diet. For pregnanolone (1-10 mg/kg), hyperphagia was found at lower doses than its anxiolytic effect (5-10 mg/kg) as determined using the elevated plus maze test. The presumed steroid antagonists, isopregnanolone (3 beta-hydroxy-5 alpha-pregnan-20-one) (10 mg/kg) and pregnenolone sulfate (2 mg/kg), and the BDZ antagonist, Ro15-1788 (20 mg/kg), did not reverse the hyperphagic effect of pregnanolone. Picrotoxin, a GABAA receptor antagonist, dose dependently and at a subconvulsive dose (1.5 mg/kg), reversed the hyperphagic effect of pregnanolone and alphaxalone, but had no effect on allopregnanolone- and 5 beta-pregnanediol-induced hyperphagia. These results indicate that the hyperphagic effects of pregnanolone and alphaxalone are mediated by the GABAA receptor but not by direct interaction with BDZ receptors. However, allopregnanolone- and 5 beta-pregnanediol-induced hyperphagia may be mediated by other receptor systems. Because some 3 alpha-hydroxylated pregnane steroids are endogenous progesterone metabolites, they may play an important role in appetite control.

Previous heat shock treatment attenuates bicuculline-induced convulsions in rats

Exposure to elevated temperature provokes a sequence of events (heat shock response) in all living organisms. Through this response, heat shock proteins (HSPs) are induced and protect the cells against subsequent injury. We investigated the effect of heat treatment on bicuculline-induced convulsions, and analyzed a possible role of HSPs. Screw electrodes were implanted in the brain of mature male Wistar rats for electroencephalogram (EEG) recording. Experimental rats were subjected to whole-body hyperthermia at 41-42 degrees C for 15 min. Fifteen hours later, bicuculline was injected intraperitoneally to induce convulsions in both experimental and control groups. The heated rats showed a significant attenuation of the convulsive response, in terms of both spike discharges in EEG and clinical seizures. Further-more, induction of HSP72 was detected in the brain of heat-treated rats by immunoblotting, appearing at 4 h and reaching a maximal level 16-24 h after the heat shock. We conclude that the previous heat treatment stabilized neuronal excitability, most probably through the induction of HSP72.

An extracellular matrix molecule that is selectively expressed during development is important for gastrulation in the sea urchin embryo

The extracellular matrix is important in the regulation of many cellular events of early development including migration, shape change, proliferation and gene expression. In the sea urchin embryo, disruption of the extracellular matrix results in selective defects in each of these events during gastrulation. Here we describe a new molecule of the extracellular matrix in Lytechinus variegatus, referred to as ECM 18, that has several important features. First, antibody interference of ECM 18 results in a profound but reversible inhibition of primary mesenchyme cell organization and endoderm morphogenesis during gastrulation. Second, during gastrulation, ECM 18 mRNA accumulates to highest levels in the invaginating endoderm and the ECM 18 protein deposited in the basal lamina surrounding the archenteron as well as in other areas of the blastocoel wall. Immunolocalization by fluorescence and electron microscopy demonstrates the selective accumulation of ECM 18 in the extracellular matrix. Third, although the mRNA encoding ECM 18 is present throughout development, the protein accumulates only during gastrulation. ECM 18 protein is not detected in eggs or early embryos and analysis of polysome-associated mRNA suggests that at least part of the translational regulation of ECM 18 is at the level of ECM 18 mRNA-polysome formation. Finally, sequence analysis of ECM 18 shows that the protein contains a repeat sequence with a conserved cysteine motif, suggestive of involvement in protein-protein interactions. Thus, ECM 18 appears to be important in mediating select morphogenetic changes during gastrulation and the pattern of its expression in the embryo is unique among the extracellular matrix molecules known in this embryo.

SO dynamic deformation for building of 3-D models

Three-dimensional (3D) modeling based on an ensemble of multilayer self-organizing (SO) neural networks is described. Our objective for 3D modeling is to construct a representation of a 3D object shape from sensed surface points acquired from the object. Current modeling techniques can be classified into two categories: the static and the dynamic approaches, where the former grounded in computational geometry, and the latter rooted in the mechanics of elastic materials. In this paper, a neural-based dynamic modeling approach is presented. The method used is proved to converge and experimental results are shown which support its applicability to real problems.

Putative benzodiazepine partial agonists demonstrate receptor heterogeneity

This study explored whether the behavioral heterogeneity of benzodiazepine receptor (BDZR) ligands is a consequence of multiple receptor subtypes or partial agonism. Putative partial agonists Ro16-6028, Ro23-1590, Ro23-0364, and abecarnil were compared with U78875, a mixed agonist-antagonist, and CGS8216, an inverse agonist, in five BDZR-mediated functions: hyperphagia, anxiolysis, sedation, hypothermia, and anticonvulsant activity. Only abecarnil was an agonist in all end points. Each of the other drugs exhibited qualitatively different responses at these end points. Specifically, Ro23-0364 produced no effect on body temperature, but was an agonist at other tests. Ro23-1590 had no effect on anxiolysis and hypothermia, but was an agonist at other tests. In contrast to other putative partial agonists, Ro16-6028 was found to be an antagonist in sedation and U78875 was an antagonist in hypothermia, but both were agonists at other end points. These qualitative differences in activity in the five behavioral end points studied cannot be explained by partial agonism at a single receptor and indicate that these ligands differentially activate multiple BDZR subtypes.

Highly efficient expression of fish growth hormone by Escherichia coli cells

A PCR product encoding the mature segment of fish pregrowth hormone (pre-GH) was inserted into an Escherichia coli expression vector, pET, in which the ori site was replaced by that of pUC19. The yield of recombinant GH (rGH) was as high as 44 to 47% of total protein. This rGH was immunoreactive to GH antibody. After renaturation, rGH was used to inject fish with 0.1 microgram of rGH per g once every 2 weeks, and this resulted in increases in weight (65%), percent weight gain (165%), and length (22%) relative to those of an untreated control group at week 16 and onward.

A behaviorally selective class of thiophene-containing benzodiazepine receptor ligands

In a continued effort to probe the role of the aromatic rings in classical 1,4-benzodiazepine (BDZ) ligand pharmacology, a series of new thiophene-containing benzodiazepine receptor (BDZR) ligands were synthesized. As a first step in determining the binding profile and selectivity to BDZR functional subtypes, the affinities in two central nervous system (CNS) regions, cerebellum, in which a single 'Type I' BDZR could be labeled; and spinal cord, in which we have previously demonstrated some receptor heterogeneity, were determined. These compounds were also assessed for their compliance with a recently developed three dimensional pharmacophore for recognition and activation of the 'Type I' BDZR, using the techniques of computational chemistry. The computations showed all ligands synthesized fulfilled the minimum requirements for recognition, further validating the current pharmacophore. Using the criteria for activation, the new ligands were all predicted to be agonists at the cerebellar 'Type I' BDZR. Since the compounds showed reasonable affinity, the behavioral profile of one of them at five in vivo endpoints was determined. This compound demonstrated more behavioral selectivity than the typical 1,4-BDZ ligand. While they fulfilled the requirements for agonist activity at the 'Type I' BDZR, these ligands showed significantly greater delocalization in the electron density distribution in the lowest unoccupied molecular orbital (LUMO), so that either aromatic ring could serve as an electron accepting site, not just the one comparable to the more classical BDZR agonist, flunitrazepam. It is possible that the ability of the second ring in the tested compound (5a) to also function as an electron acceptor can affect the recognition and activation of other receptor types leading to the more discriminate behavioral profile of this thiophene analog compared to flunitrazepam.

Cytokine regulation of HIV-1 LTR transactivation in human hepatocellular carcinoma cell lines

Human hepatocellular carcinoma (HCC) cell lines, HEP-G2, J5, and SK-HEP-1, which differ in their differentiation status, were compared for their trans-activating activities after treatment with cytokines or 12-O-tetradecanoylphorbol-13-acetate (TPA). These cells were transfected with a long terminal repeat (LTR) which was derived from human immunodeficiency virus type 1 (HIV-1) and ligated to chloramphenicol acetyl transferase (CAT) gene. After treatment with interleukin-1 alpha (IL-1 alpha), interleukin-6 (IL-6), interferon-gamma (IFN-gamma), or TPA, they exhibited various degrees of enhancement of transactivation. The well differentiated HEP-G2 cells exhibited the highest degree of enhancement with these agents, while the poorly differentiated SK-HEP-1 cells showed no enhancement with cytokines and slight enhancement with TPA. The J5 cells, which were intermediate in their status of differentiation, showed a moderate degree of enhancement with cytokines and TPA. These results suggest that HCC cells at different stages of differentiation may produce different levels of cellular transacting factors activated by each of these agents. To map the cytokine response elements (CREs) in the HIV-1-LTR, HEP-G2 cells were transfected with nested series of 5' deletion mutants of HIV-1-LTR and treated with each of these cytokines. It was found that not only the degrees but also the patterns of enhancement varied depending upon the presence of positive or negative regulatory sequences in HIV-1-LTR, and that the NF-kappa B sequence played an important role, either by itself or in conjunction with the 5'-proximal response elements (REs) to interact with cellular trans-activating factors elicited by the cascade of transduction responses to cytokines. Despite the presence of promoters including kappa B and IFN-gamma RE as well as IL-6RE sequence in HIV-1-LTR-transfected cells, the poorly differentiated SK-HEP-1 cells showed no enhancement of transactivation by these cytokines, suggesting the lack of receptors or activity of some signal transduction factors which are present in well differentiated HEP-G2 and moderately differentiated J5 cells.

A Combinatorial Approach to Materials Discovery

A method that combines thin film deposition and physical masking techniques has been used for the parallel synthesis of spatially addressable libraries of solid-state materials. Arrays containing different combinations, stoichiometries, and deposition sequences of BaCO(3), Bi(2)O(3), CaO, CuO, PbO, SrCO(3), and Y(2)O(3) were generated with a series of binary masks. The arrays were sintered and BiSrCaCuO and YBaCuO superconducting films were identified. Samples as small as 200 micrometers by 200 micrometers in size were generated, corresponding to library densities of 10,000 sites per square inch. The ability to generate and screen combinatorial libraries of solid-state compounds, when coupled with theory and empirical observations, may significantly increase the rate at which novel electronic, magnetic, and optical materials are discovered and theoretical predictions tested.

Food palatability and hunger modulated effects of CGS 9896 and CGS 8216 on food intake

The effect of food palatability and duration of food deprivation on the modulation of food intake by two benzodiazepine receptor (BDZR) ligands, CGS 9896 and CGS 8216, were investigated. Three diets differing in palatability (high, medium, or standard) and three different periods of food deprivation (0, 16, or 24 h) were used in all combinations to compare the effect of these variations on the observed modulation of food consumption by both BDZR ligands. Increasing diet palatability and/or food deprivation increased the baseline food consumption and reduced the sensitivity of the test to the detection of the hyperphagic effect of CGS 9896 but increased the sensitivity to detect the anorexic effect of CGS 8216. Only for the intermediate conditions of food deprivation (16 h) and for a standard or medium palatable diet were both significant hyperphagic effect of CGS 9896 and anorexic effect of CGS 8216 detected. Neither increased palatability nor hunger enhanced the modulation of feeding, indicating that neither "taste preference" nor "hunger" is the key factor in the mechanism of BDZR ligand-induced feeding response.