A Qualitative Investigation of the Impact of Home-Based Primary Care on Family Caregivers.

BACKGROUND: Home-based primary care (HBPC) provides team-based clinical care for homebound patients who have difficulty accessing typical outpatient care. Interdisciplinary team members also provide social and emotional support and serve as a resource for family caregivers, who often experience significant emotional stress. OBJECTIVES: This qualitative study explores the impact of HBPC on family caregivers to identify aspects of the program that caregivers find most helpful and meaningful as well as areas for improvement. DESIGN: Semi structured recorded interviews were conducted with family caregivers of frail, elderly homebound patients. Interviews included the following topics: overall program satisfaction and suggestions for improvement. SETTING: A HBPC program serving patients in Queens, Nassau and Suffolk counties in New York. PARTICIPANTS: Nineteen family caregivers: 13 women, 6 men; 10 were adult children; 6 were spouses, and 3 were other family members of patients in a HBPC program. MEASUREMENTS: Thematic coding of all recorded transcribed interviews was prepared by 3 qualitative coders. Interrater reliability was conducted to ensure reliability across coders before themes were disseminated and discussed until consensus was achieved with the larger group of investigators. RESULTS: Three main themes were identified: the importance of staff emotional support; the burden of caring for homebound patients; and the need for a broader range of home-based services. Multiple family members noted that the program not only had saved their loved one's life, but had also metaphorically saved their own. CONCLUSIONS: Family caregivers value the communication and accessibility of HBPC and report that the program has a positive impact on their stress and mental health. Results can inform key aspects that need to be retained or enhanced with the expansion in HBPC programs.

Enhanced binding of metabotropic glutamate receptor type 5 (mGluR5) PET tracers in the brain of parkinsonian primates.

The interplay between dopamine and glutamate in the basal ganglia regulates critical aspects of motor learning and behavior. Metabotropic glutamate receptors (mGluR) are increasingly regarded as key modulators of neuroadaptation in these circuits, in normal and disease conditions. Using PET, we demonstrate a significant upregulation of mGluR type 5 in the striatum of MPTP-lesioned, parkinsonian primates, providing the basis for therapeutic exploration of mGluR5 antagonists in Parkinson disease.

Cellular sensitization to cis-diamminedichloroplatinum(II) by novel analogues of the protein kinase C activator lyngbyatoxin A.

Protein kinase C (PKC) has been implicated in enhancing cellular sensitivity to cis-diamminedichloroplatinum(II) (CP). We have synthesized a series of novel analogues of lyngbyatoxin A (7-linalylindolactam V), a natural tumor promoter and a potent activator of PKC, and investigated the effects of these synthetic compounds on PKC activity and the antiproliferative activity of CP. Lyngbyatoxin A was as effective as phorbol esters, such as 12-O-tetradecanoylphorbol-13-acetate, in enhancing the sensitivity of HeLa cells to CP. A 24-h pretreatment of HeLa cells with 1 to 100 nM lyngbyatoxin A caused an approximately 9-fold sensitization to CP. All analogues of lyngbyatoxin A that retained the lactam ring portion of the molecule but contained different hydrophobic substituents at C-7 including indolactam V (ILV), tert-butyl-ILV, or n-hexyl-ILV increased cellular sensitivity to CP in a concentration-dependent manner. Maximum cellular sensitization to CP (9-fold) was seen with 10 nM n-hexyl or tert-butyl compounds, and ILV devoid of any C-7 substitution required higher concentrations (1 microM) for equivalent sensitization. The ability of lyngbyatoxin A analogues to sensitize cells to CP correlated directly with their ability to activate PKC in vitro. Synthetic analogues that lacked the lactam ring structure neither activated PKC nor sensitized cells to CP. The C-9 epi analogue of n-hexyl-ILV was less effective than the corresponding natural stereoisomer in activating PKC as well as sensitizing cells to CP. Exposure of HeLa cells to 100 nM lyngbyatoxin A for 24 h caused a substantial decrease in cellular PKC activity to 20% of the untreated control value, but a similar treatment of cells with n-hexyl- or tert-butyl-ILV led to only a 25% reduction in PKC activity. Concentrations of ILV (e.g. 1 microM) that sensitized HeLa cells to CP caused no down-regulation of PKC. Thus, on the basis of results with these novel lyngbyatoxin A analogues, we conclude that activation but not down-regulation of PKC is necessary for sensitization of HeLa cells to CP.

Targeting histone deacetylase 6 mediates a dual anti-melanoma effect: Enhanced antitumor immunity and impaired cell proliferation.

The median survival for metastatic melanoma is in the realm of 8-16 months and there are few therapies that offer significant improvement in overall survival. One of the recent advances in cancer treatment focuses on epigenetic modifiers to alter the survivability and immunogenicity of cancer cells. Our group and others have previously demonstrated that pan-HDAC inhibitors induce apoptosis, cell cycle arrest and changes in the immunogenicity of melanoma cells. Here we interrogated specific HDACs which may be responsible for this effect. We found that both genetic abrogation and pharmacologic inhibition of HDAC6 decreases in vitro proliferation and induces G1 arrest of melanoma cell lines without inducing apoptosis. Moreover, targeting this molecule led to an important upregulation in the expression of tumor associated antigens and MHC class I, suggesting a potential improvement in the immunogenicity of these cells. Of note, this anti-melanoma activity was operative regardless of mutational status of the cells. These effects translated into a pronounced delay of in vivo melanoma tumor growth which was, at least in part, dependent on intact immunity as evidenced by the restoration of tumor growth after CD4+ and CD8+ depletion. Given our findings, we provide the initial rationale for the further development of selective HDAC6 inhibitors as potential therapeutic anti-melanoma agents.

Identification of amino acid residues involved in the binding of Huperzine A to cholinesterases.

Huperzine A, a potential agent for therapy in Alzheimer's disease and for prophylaxis of organophosphate toxicity, has recently been characterized as a reversible inhibitor of cholinesterases. To examine the specificity of this novel compound in more detail, we have examined the interaction of the 2 stereoisomers of Huperzine A with cholinesterases and site-specific mutants that detail the involvement of specific amino acid residues. Inhibition of fetal bovine serum acetylcholinesterase by (-)-Huperzine A was 35-fold more potent than (+)-Huperzine A, with KI values of 6.2 nM and 210 nM, respectively. In addition, (-)-Huperzine A was 88-fold more potent in inhibiting Torpedo acetylcholinesterase than (+)-Huperzine A, with KI values of 0.25 microM and 22 microM, respectively. Far larger KI values that did not differ between the 2 stereoisomers were observed with horse and human serum butyrylcholinesterases. Mammalian acetylcholinesterase, Torpedo acetylcholinesterase, and mammalian butyrylcholinesterase can be distinguished by the amino acid Tyr, Phe, or Ala in the 330 position, respectively. Studies with mouse acetylcholinesterase mutants, Tyr 337 (330) Phe and Tyr 337 (330) Ala yielded a difference in reactivity that closely mimicked the native enzymes. In contrast, mutation of the conserved Glu 199 residue to Gln in Torpedo acetylcholinesterase produced only a 3-fold increase in KI value for the binding of Huperzine A.(ABSTRACT TRUNCATED AT 250 WORDS)

Defining the minimal structural requirements for partial agonism at the type I myo-inositol 1,4,5-trisphosphate receptor.

The novel synthetic analogues D-3-fluoro-myo-inositol 1,5-bisphosphate-4-phosphorothioate, [3F-Ins(1,5)P2-4PS], D-3-fluoro-myo-inositol 1,4-bisphosphate-5-phosphorothioate [3F-Ins(1,4)P2-5PS], and D-3-fluoro-myo-inositol 1-phosphate-4,5-bisphosphorothioate [3F-Ins(1)P-(4,5)PS2] were utilised to define the structure-activity relationships which could produce partial agonism at the Ca2+ mobilising myo-inositol 1,4,5-trisphosphate [Ins(1,4,5)P3] receptor. Based on prior structure-activity data we hypothesised that the minimal structural requirements for lns(1,4,5)P3 receptor partial agonism, were phosphorothioate substitution of the crucial vicinal 4,5-bisphosphate pair accompanied by another structural perturbation, such fluorination of 3-position of the myo-inositol ring. All the analogues fully displaced [3H]Ins(1,4,5)P3 from a single Ins(1,4,5)P3 binding site in pig cerebellar membranes [3F-Ins(1,5)P2-4PS (1C50 = 26 nM), 3F-Ins(1,4)P2-5PS (IC50 = 80 nM) and 3F-Ins(1)P-(4,5)PS2 (IC50 = 109 nM) cf. Ins(1,4,5)P3 (IC50 = 11 nM)]. In contrast, 3F-Ins(1,5)P2-4PS (IC50 = 424 nM) and 3F-Ins(1,4)P2-5PS (IC50 = 3579 nM) were weak full agonists at the Ca2+ mobilising Ins(1,4,5)P3 receptor of permeabilised SH-SY5Y neuroblastoma cells, being respectively 4- and 36-fold less potent than Ins(1,4,5)P3 (EC50 = 99 nM). While 3F-Ins(1)P-(4,5)PS2 (EC50 = 11345 nM) was a partial agonist releasing only 64.3 +/- 1.9% of the Ins(1,4,5)P3-sensitive intracellular Ca2+ pools. 3F-Ins(1)P-(4,5)PS2 was unique among the Ins(1,4,5)P3 receptor partial agonists so far identified in having a relatively high affinity for the Ins(1,4,5)P3 binding site, accompanied by a significant loss of intrinsic activity for Ca2+ mobilisation. This improved affinity was probably due to the retention of the 1-position phosphate, which enhances interaction with the Ins-(1,4,5)P3 receptor. 3F-Ins(1)P-(4,5)PS2 may be an important lead compound for the development of efficient Ins(1,4,5)P3 receptor antagonists.

Metabotropic glutamate receptor agonist trans-azetidine-2,4-dicarboxylic acid facilitates maintenance of LTP in the dentate gyrus in vivo.

We examined the role of metabotropic glutamate receptors by studying the effect of intracerebroventricular infusion of the putative mGluR agonist trans-azetidine-2,4-dicarboxylic acid (tADA) on long-term potentiation (LTP) in the dentate gyrus of freely moving rats. Weak tetanization caused a decremental potentiation which returned to baseline levels within 2 hr. Injections of tADA (20 mM/5 microliters) 30 min prior to weak tetanization prolonged LTP of the field EPSP for at least 24 hr.

Block of spatial learning by mGluR agonist tADA in rats.

As demonstrated recently, mGluRs are involved in some forms of learning. We thus investigated the effect of tADA (trans-azetidine-2,4-dicarboxylic acid) applied intracerebroventricularly prior to learning a spatial alternation paradigm. Compared to controls, tADA treated animals were amnesic when tested for retention 24 hr after training. Effects of state-dependency were excluded. These data and our earlier work indicate that both mGluR agonists and antagonists can have memory-disrupting effects.

Neurochemistry of aging. 2. Design, synthesis, and biological evaluation of halomethyl analogues of choline with high affinity choline transport inhibitory activity.

The design, synthesis, and testing of several halomethyl analogues of choline and acetylcholine as potential cholinotoxins is described. The compounds were evaluated for their ability to inhibit high-affinity choline transport and their affinity toward postsynaptic muscarinic receptors. Among the analogues tested, bromomethyl and iodomethyl analogues of choline were found to be the most potent inhibitors of the high affinity choline transport system. Introduction of a beta-methyl group in the halomethyl analogues drastically reduced their potencies. The bromomethyl and iodomethyl analogues were further investigated for their effects on choline acetyltransferase activity, acetylcholinesterase activity and QNB binding. Neither compound possesses significant ability to alter any of the above cholinergic markers, except at very high concentrations. These results suggest that the bromomethyl and iodomethyl choline analogues may be used as specific inhibitors of the presynaptic high-affinity choline transport system.

Synthesis of structural analogues of lyngbyatoxin A and their evaluation as activators of protein kinase C.

Syntheses of several new analogues of lyngbyatoxin A from a single common intermediate are described. These compounds bear a carbon chain at the 7-position of the indolactam V (ILV) nucleus which contains either a hydrophilic or a lipophilic group. The effect of these minor structural alterations on the ability of the ILV analogues to activate the enzyme protein kinase C (PKC) was determined by measuring the extent of phosphorylation of calf thymus histone (III-S). Introduction of a hydroxyl group on the C-7 appendage was found to dramatically decrease compound 3's ability to activate PKC. This result is interpreted in terms of the decreased ability of 3 to associate with the membrane bilayer.

Synthesis and bioactivity of a new class of rigid glutamate analogues. Modulators of the N-methyl-D-aspartate receptor.

A variety of derivatives of azetidine-2,4-dicarboxylic acid were synthesized and examined for their ability to stimulate 45Ca2+ uptake in cultures of cerebellar granule cells. Of the compounds tested, the cis-azetidine-2,4-dicarboxylic acid (10f) was found to be the most potent agent in potentiating glutamate, aspartate, or N-methyl-D-aspartate (NMDA) stimulated 45Ca2+ uptake at the NMDA receptor. The mechanism of action of 10f was further investigated in [3H]MK-801 binding assays and [3H]GABA release from cultured embryonic rat forebrain neurons. All of the results from the functional studies of azetidine 10f are consistent with a selectivity of action at the NMDA receptor. Moreover, azetidine 10f appears to exhibit a dual type of action, behaving as a glutamate-like agonist at higher concentrations and as a positive modulator at concentrations below 50 microM.

Chemistry, binding affinities, and behavioral properties of a new class of "antineophobic" mitochondrial DBI receptor complex (mDRC) ligands.

The mitochondrial DBI receptor complex (mDRC; previously called the peripheral benzodiazepine receptors) is linked to the production of neurosteroids such as pregnenolone sulfate, dehydroepiandrosterone sulfate, and others. In order to gain further information as to the function of the mDRC in the brain, we have constructed and tested both in vitro and in vivo a novel series of ligands, 2-arylindole-3-acetamides. The SAR studies detailed herein delineate some of the structural features required for high affinity binding to the mDRCs. In most cases the new ligands were prepared by use of the Fischer indole synthesis. Variations in the length and number of the alkyl groups on the amide nitrogen were probed together with the effects of halogen substituents on one or both of the aryl rings. Some ligands were also synthesized for study which represent conformationally constrained versions of the parent structure. Broad screening studies revealed these indoleacetamides to be highly selective for the mDRC, since they failed to bind with any significant affinity to other receptor systems. Some of the ligands were found to exhibit Ki values in the low nanomolar range for the mDRC as measured by the displacement of [3H]4'-chlorodiazepam. A subset of these ligands was also shown to stimulate pregnenolone formation from the mitochondria of C6-2B glioma cells with an EC50 of about 3 nM. In animal experiments ligands selected for further study were found to exhibit antineophobic effects, in spite of the fact that they exhibit no direct action on GABAA receptors. Consequently, it is postulated that these ligands owe their action to an indirect modulation of GABAA receptor function, presumably by stimulation of neurosteroid production and release from glial cells, followed by neurosteroid modulation of GABA's action on the chloride ion channel conductance of GABAA receptors.

Chemistry and biology of the 2 beta-alkyl-3 beta-phenyl analogues of cocaine: subnanomolar affinity ligands that suggest a new pharmacophore model at the C-2 position.

A series of 2 beta-alkyl-3 beta-phenyltropanes (i.e., the 2 beta-alkyl analogues of the WIN series) were prepared as analogues of cocaine and tested for their ability to displace [3H]mazindol binding and to inhibit high-affinity dopamine uptake into striatal nerve endings (synaptosomes). These 2 beta-alkyl analogues were readily prepared in optically pure form starting from cocaine by proceeding through the 2 beta-phenyl-bearing aldehyde 6 as a key intermediate. Wittig reaction of 6 with the appropriate phosphorane and hydrogenation delivered the final products. All new compounds with the exception of 8e were found to exhibit nanomolar or subnanomolar affinity for the cocaine binding site in the rat striatum. These results are in apparent opposition to the binding model previously proposed which suggests a hydrogen bond donor-acceptor interaction to be present in the vicinity of the C-2 substituent. Taken together with our previous reports and recent findings from other laboratories, we suggest a new pharmacophore model in which 2 beta-substituents lacking H-bond acceptors enhance affinity to the binding site through hydrophobic interactions. The new SAR data contained herein may be relevant to the design of possible cocaine antagonists.

Novel conformationally constrained tropane analogues by 6-endo-trig radical cyclization and stille coupling - switch of activity toward the serotonin and/or norepinephrine transporter.

A novel class of tricyclic tropane analogues has been synthesized by making use of radical cyclization technology in combination with the Stille coupling reaction. As hybrids between tropanes and quinuclidines, these tropaquinuclidines represent a significant structural departure from many of the other classes of tropane ligands synthesized to date. This structure class is characterized by the boat conformation of the tropane ring and the orientation of the additional bridge (and therefore of the nitrogen lone pair) together with the unusual placement of the aromatic moiety. All compounds were tested for their ability to inhibit monoamine reuptake under identical conditions. The ability to inhibit reuptake of dopamine in comparison to cocaine is generally decreased in this series but for one compound. (1S,3R, 6S)-(Z)-9-(thienylmethylene)-7-azatricyclo[4.3.1.0(3, 7)]decane-2beta-carboxylic acid methyl ester (5h) exhibits reasonable activity at the dopamine transporter (DAT) (K(i) = 268 nM) and good activity at the norepinephrine transporter (NET) (K(i) = 26 nM). The potency and selectivity shown by some of these ligands for the NET, serotonine transporter (SERT), or NET/SERT is striking, particularly in view of the displacement of the aromatic ring in this series from its usual position at C-3 in the WIN analogues. Thus, (1S,3R,6S)-(Z)-9-(4-biphenylylmethylene)-7-azatricyclo[4.3.1 . 0(3,7)]decane-2beta-carboxylic acid methyl ester (5a) is a selective inhibitor of norepinephrine reuptake (K(i) = 12 nM). Its p-methoxy analogue 5c is a mixed inhibitor of norepinephrine and serotonin reuptake (K(i) = 187 nM at the NET and 56 nM at the SERT). The most active and selective compound we found in the present series is compound 8b [(1S,3R,6S)-2-(acetoxymethyl)-(Z)-9-(3, 4-dichlorophenylmethylene)-7-azatricyclo[4.3.1.0(3,7)]decane ]. This compound is a potent (K(i) = 1.6 nM) and selective inhibitor of serotonin reuptake into rat midbrain synaptosomes. Its selectivity is about 400-fold over the NET and about 1000-fold over the DAT. The results of this study further demonstrate the possibility of tuning the selectivity of tropane analogues toward the SERT or NET binding site. The ligands disclosed herein provide additional pharmacological tools of use in attempting to correlate structure and transporter selectivity with in vivo studies of behavioral outcomes.

Chemical synthesis and pharmacology of 6- and 7-hydroxylated 2-carbomethoxy-3-(p-tolyl)tropanes: antagonism of cocaine's locomotor stimulant effects.

In our efforts to identify molecules that might act as cocaine antagonists or cocaine partial agonists, efforts were made to further capitalize on our earlier finding regarding the ability of a 7-methoxylated pseudococaine analogue to act as a weak cocaine functional antagonist. Herein, a series of the 6- and 7-hydroxylated WIN analogues possessing a boat or chair conformation of the tropane ring were prepared and tested for their ability to displace [(3)H]mazindol binding and to inhibit high-affinity monoamine uptake into rat brain nerve endings. These 6- and 7-hydroxylated WIN analogues were readily prepared by use of a classical Willstätter synthesis to construct an appropriately functionalized tropane ring followed by use of a Suzuki coupling reaction to introduce the aryl group at position 3. Reduction of the resulting tropene by use of SmI(2) or by catalytic hydrogenation followed by deprotection delivered the final target compounds. Some of these compounds were found to retain considerable affinity as inhibitors of the dopamine transporter (DAT) and the norepinephrine transporter (NET), but they were less potent inhibitors of the serotonin transporter (SERT). None of the compounds of the present series revealed any substantial potency difference in [(3)H]mazindol binding versus [(3)H]DA uptake, and failed to show "cocaine antagonism" when tested for their ability to prevent cocaine's inhibition of DA transport. However, one of these hydroxylated WIN analogues, namely 12b, which possesses nanomolar potency at the DAT and NET and micromolar potency at the SERT, when tested in vivo, was found capable of attenuating cocaine's locomotor activity (AD(50) = 94 mg/kg). Taken together, this work provides further support for our hypothesis that drugs that lack the ability to inhibit transport by all three monoaminergic transporters may exhibit "partial" cocaine-like properties, but act as cocaine antagonists. Consequently, it may prove valuable to examine the behavioral activity of other 6- and 7-substituted tropanes in animal behavioral paradigms in the search for a cocaine medication.

Structure-activity relationship studies of N-sulfonyl analogs of cocaine: role of ionic interaction in cocaine binding.

Six new N-sulfonylated analogs of cocaine have been prepared, and these compounds have been evaluated for their ability to inhibit [3H]mazindol binding and [3H]dopamine uptake into striatal synaptosomes. The N-sulfonyl compounds still inhibited binding and uptake at low micromolar concentrations despite the neutral character of the tropane nitrogen, thus suggesting that the binding of cocaine to the dopamine transporter may not require protonation of its nitrogen and ionic interaction with its recognition site.

Synthesis and biological properties of new 2beta-alkyl- and 2beta-aryl-3-(substituted phenyl)tropane derivatives: stereochemical effect of C-3 on affinity and selectivity for neuronal dopamine and serotonin transporters.

In our efforts to identify molecules that might act as cocaine antagonists or cocaine partial agonists, we have been involved in efforts to further elucidate the nature of cocaine's binding to the dopamine transporter (DAT) through strategic modifications of its structure. In the case of the substituent located at the 2-position of the tropane ring, studies have revealed the ability of the transporter to accommodate groups of diverse structure, including ester, ketone, alkyl, alkenyl, heterocyclic, and aryl substituents, without loss of DAT binding affinity. In the present study, we report our results pertaining to the ability of the DAT to accommodate the WIN-type structures possessing alkyl or aryl groups at the 2-position and which adopt either a chair or a boat conformation of the tropane ring. Moreover, we discuss the influence of the stereochemistry of these compounds in their selectivity for the DAT versus the serotonin transporter (5HTT). Additionally, we point out the importance of using Ki values rather than IC50 values when making such comparisons of transporter selectivity. One of the most interesting compounds identified in the present work is a 2, 3-diaryltropane 22 in a boat conformation that is highly selective (69-fold) for the DAT over the 5HTT. The ability to prepare this compound as well as related structures by our oxidopyridinium betaine-based dipolar cycloaddition strategy further underscores the versatility of this particular chemical approach to the preparation of diverse tropane analogues. The use of the optically pure olefin p-tolyl vinyl sulfoxide as the dipolarophile in this reaction allows access to these novel tropanes in nonracemic form.

The novel Ins(1,4,5)P3 analogue 3-amino-3-deoxy-Ins(1,4,5)P3: a pH-dependent Ins(1,4,5)P3 receptor partial agonist in SH-SY5Y neuroblastoma cells.

We have synthesized the first amino-substituted inositol 1,4,5-trisphosphate [Ins(1,4,5)P3] analogue, D-3-amino-3-deoxy-myo-Ins(1,4,5)P3 (9). Although 9 is a full agonist at the Ca2+ mobilizing Ins(1,4,5)P3 receptor at pH 7.2 and 7.6, it is apparently a high intrinsic activity partial agonist at pH 6.8, releasing only 80% of the Ins(1,4,5)P3-sensitive Ca2+ stores of SH-SY5Y cells. Additionally, 9 was able to fully displace [3H]Ins(1,4,5)P3 from binding sites in rat cerebellum membranes at both pH 6.8 and 7.6, indicating a full interaction with the Ins(1,4,5)P3 receptor. The activity displayed by this amino analogue is unexpected and may be indicative of a pH-dependent conformational change in the amino acid residues comprising the Ins(1,4,5)P3 binding site.

3-(Hydroxymethyl)-bearing phosphatidylinositol ether lipid analogues and carbonate surrogates block PI3-K, Akt, and cancer cell growth.

Phosphatidylinositol 3-kinase (PI3-K) phosphorylates the 3-position of phosphatidylinositol to give rise to three signaling phospholipids. Binding of the pleckstrin homology (PH) domain of Akt to membrane PI(3)P's causes the translocation of Akt to the plasma membrane bringing it into contact with membrane-bound Akt kinase (PDK1 and 2), which phosphorylates and activates Akt. Akt inhibits apoptosis by phosphorylating Bad, thus promoting its binding to and blockade of the activity of the cell survival factor Bcl-x. Herein we present the synthesis and biological activity of several novel phosphatidylinositol analogues and demonstrate the ability of the carbonate group to function as a surrogate for the phosphate moiety. Due to a combination of their PI3-K and Akt inhibitory activities, the PI analogues 2, 3, and 5 proved to be good inhibitors of the growth of various cancer cell lines with IC(50) values in the 1-10 microM range. The enhanced Akt inhibitory activity of the axial hydroxymethyl-bearing analogue 5 compared to its equatorial counterpart 6 is rationalized based upon postulated differences in the H-bonding patterns of these compounds in complex with a homology modeling generated structure of the PH domain of Akt. This work represents the first attempt to examine the effects of 3-modified PI analogues on these two crucial cell signaling proteins, PI3-K and Akt, in an effort to better understand their cell growth inhibitory properties.

Synthesis and biological activity of 8a-phenyldecahydroquinolines as probes of PCP's binding conformation. A new PCP-like compound with increased in vivo potency.

The synthesis and chemical resolution of cis- and trans-fused 8a-phenyldecahydroquinolines 3 and 4 are described together with the affinity of the four optically pure compounds for the PCP recognition site of the NMDA receptor complex. These compounds were also evaluated for their antagonistic effects on cGMP levels in male Swiss Webster mice, and (-)-4 was found to exhibit in vivo potency comparable to that of MK-801. The results of the binding studies are interpreted in terms of a preferred orientation of PCP's N-H bond in binding to its NMDA receptor-associated recognition site.