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Biomedical subjects

P Arya

Publications and source records attributed to P Arya.

17 recordsLinked to original sources
PubMed2006

Pharmacological management of akathisia in combination with psychological interventions by a mental health nurse consultant.

The article describes the management of akathisia by a mental health nurse (MHN) prescriber, working in partnership with the patient. A single-case design was used to evaluate this. It highlights three features: first, MHN can safely prescribe psychiatric medication in combination with concordance therapy. Second, the value base underpinning prescribing practice is partnership, honesty and choice for the patient. Finally, the pharmacological mechanism of antipsychotic medication, which contributes towards akathisia, requires further analysis.

Akathisia, Drug-Induced↗
PubMed2001

Combinatorial chemistry toward understanding the function(s) of carbohydrates and carbohydrate conjugates.

Combinatorial chemistry has contributed significantly to understanding the structure-function relationships of biologically important molecules such as proteins and nucleic acids. However, carbohydrates and carbohydrate conjugates, which have been identified as key modulators of several biological functions have not enjoyed the same measure of success. The complexity and synthetic challenges of carbohydrate conjugates have resulted in a number of conceptual approaches to rapidly access sufficient quantities of these biomolecules. This article summarizes these combinatorial approaches and also highlights fully automated library synthesis of artificial glycopeptides with the goals of understanding their biological roles.

Carbohydrate Conformation↗
PubMed2001

Natural-product-like chiral derivatives by solid-phase synthesis.

In this genomics and proteomics age, highly functionalized natural products or natural-product-like compounds are likely to play important roles in understanding the functions of emerging biological targets because they serve as small-molecule chemical probes in modulating a target's specific actions (i.e. activation or deactivation). Development of stereoselective reaction-derived methods on solid phase provides a means of obtaining functionalized chiral core structures that may be used for high-throughout syntheses.

Animals↗
PubMed1999

Alpha-galactose based neoglycopeptides. Inhibition of verotoxin binding to globotriosylceramide.

Solution and solid phase strategies for the synthesis of alpha-galactose based neoglycopeptide derivatives 2-13 were developed. Neoglycopeptides generated were tested for the inhibition of verotoxin binding to globotriosylceramide (Gb3) using ELISA. Among all of the compounds tested, only the lipid derivatives of neoglycopeptides, 11, 12 and 13 were found to be inhibitors, IC50 = 2.0 mM (11b and 12c) and 0.2 mM (11c and 13c). All of the inhibitors (11b, 11c, 12c and 13c) have a similar branching of the two alpha-galactosyl units at the N-terminal glycine residue of a short peptide and a lipid moiety attached at the C-terminal site. Both of these factors seem to be crucial for the inhibition. It is interesting to note that the inhibitors have only a portion of the natural trisaccharide ligand. The secondary groups either may contribute in sub-site oriented interactions with the protein receptors or may mimic the internal sugar units of the cell-surface ligand, Gb3.

Anti-Infective Agents↗
PubMed1998

Design and synthesis of analogs of vitamin E: antiproliferative activity against human breast adenocarcinoma cells.

Analogs of alpha-tocopherol (vitamin E; compounds 3-9) have been synthesized and tested for their antiproliferative activity using the human breast cancer cell line, MCF7. Compounds 6-9 were synthesized from a common symthom, rac-Trolox (14) and are soluble/miscible at physiological pH. Compounds 4, 8, and 9 were found to have antiproliferative activity at micromolar concentrations.

Adenocarcinoma↗
PubMed1998

Diversity of C-linked neoglycopeptides for the exploration of subsite-assisted carbohydrate binding interactions.

Diversity of alpha-galactose based C-linked neoglycopeptides (1b, 2b, 3c, 4d, and 5d) has been developed to explore the importance of subsite-assisted carbohydrate binding interactions. Deprotected C-linked neoglycopeptides (1b, 2b, 3c, 4d, and 5d) were synthesized and tested in competitive inhibition assays using a model enzyme-linked lectin (e.g., Maclura pomifera). Compound 2b, with two alpha-galactoside units on the side chain of the lysine residue of the dipeptide backbone, exhibited a remarkable effect with a 2.82-fold increase in its inhibitory properties (IC50 1.48 mM) in comparison to 1b (IC50 4.18 mM).

Binding Sites↗
PubMed1996

Excess bioavailability of zinc may cause obesity in humans.

The body weight or body weight/height ratio exhibits a positive linear correlation to hair zinc (Zn) concentration which is more strongly positive in men than in women. The obese of both sexes possess higher Zn concentrations in their hair than those with normal body weight/height. The degree of obesity increases with the increase in the hair Zn concentration.

Adult↗
PubMed1995

Lipid-zinc interaction: its effect on the testes of mice.

Lipid-Zn interaction in the testes of mice was studied by feeding them low-fat (30 g maize oil/kg; group LFZD) and high-fat (90 g maize oil/kg; group HFZD) Zn-deficient diets for 6 weeks. The results were compared with those of corresponding Zn-supplemented-diet-fed controls (groups LFZS and HFZS). The integument-related Zn-deficiency symptoms appeared in group HFZD and not in group LFZD mice despite lack of Zn in their ration and an equal level of Zn in their blood serum. The feed intake, gain in body weight and testes weight of the LFZD group were comparable with those of the LFZS and HFZS groups (P > 0.05) but were higher than those of the group HFZD (P < 0.05). The testes of group HFZD displayed necrotic changes marked by the presence of giant cells, lower RNA, DNA and protein concentrations and higher phospholipid and cholesterol levels than those of mice in the LFZD group. The concentrations of these fractions were not significantly different between LFZD and HFZS. The results do not support the hypothesis that Zn is essential either for testicular function or for nucleic acid and protein synthesis in animals fed on a low-fat diet; however, it appears to be essential for animals fed on a high-fat diet. The changes observed in the testes of the HFZD animals suggest the excess intake of fat as their cause in Zn-deficient animals.

Animals↗
PubMed1994

Lipid deposition in intestine as a possible cause of malabsorption of nutrients in zinc-deficient common carp (Cyprinus carpio).

An experiment was performed to examine the interaction between Zn deficiency and lipid intake in carp. The carp were given a high-lipid diet that was either Zn-deficient (ZD) or Zn-supplemented (ZS), or were pair-fed (PF) the ZS diet to the intake of the ZD group. After 8 weeks the carp were killed and measurements were made of intestinal glucose uptake, levels of DNA, RNA and triacylglycerol, and alkaline phosphatase (EC 3.1.3.1) activity in liver and intestine samples. A further group of similar carp were given the same diets but at week 8 were transferred to low-lipid diets, with the exception of half the ZD group. After a further 8 weeks of treatment, carps were killed for biochemical studies. Intestinal [14C]glucose uptake, levels of DNA, RNA and alkaline phosphatase activity in intestine and liver were significantly (P < 0.05) lower in the high-lipid ZD group than in the high-lipid ZS and PF diet groups. The triacylglycerol concentration in the intestine was higher in the high-lipid ZD group than in the other two groups. When the carp were given the corresponding low-lipid diets, the variables measured in intestine and liver of the ZD group were close to those of the other groups. The results of this study demonstrate that lipid, when present in excess in the diet, accumulates in the intestine under Zn-deficient conditions and may reduce the absorption of glucose in carp. The reduced RNA and DNA levels and alkaline phosphatase activity in liver and intestine of ZD fish compared with those of ZS fish given high-lipid diets is proposed to be due to the malabsorption of nutrients linked with lipid deposition in the intestine, rather than their dependence on the level of Zn in the diet.

Alkaline Phosphatase↗
PubMed1992

Influence of low dietary lipid content on anorexia and [14C]glucose uptake in the intestine of zinc-deficient mice.

Zinc deficiency was induced in adult male mice by feeding them for 8 weeks on a purified semi-synthetic Zn-deficient diet (ZD) containing 90 g lipid/kg (60 g maize oil plus 30 g cod-liver oil). One group was then fed on a low-lipid Zn-deficient diet (ZDLR) containing 30 g cod-liver oil/kg as the sole lipid source for a further 8 weeks. At the end of the experiment the stomach clearance rate, daily food intake, body-weight gain and [14C]glucose uptake in the intestine were significantly higher in group ZDLR than in mice that continued eating the Zn-deficient lipid-adequate diet ZD, and were comparable to results for a group given a Zn-supplemented diet. These results suggest that the pathogenesis of anorexia, nutrient malabsorption and growth retardation are secondary to lipid malabsorption resulting from Zn deficiency.

Animals↗
PubMed1992

Inanition may reduce alkaline phosphatase activity in liver and intestine of zinc-deficient mice.

Zinc-deficiency was induced in mice by feeding a Zn-deficient basal diet (ZD dietary group) containing 9% lipid (6% corn oil, 3% cod liver oil) for 8 wk. Thereafter, the corn oil was withdrawn from the basal diet and a subset of Zn-deficient animals (ZDLR group) was fed this modified low fat diet for another 8 wk. Alkaline phosphatase activity in intestine and liver was compared in these mice and in those allowed ad libitum access to the lipid-adequate Zn-supplemented diet (ZS group), in those pair-fed the Zn-supplemented diet (PF group) and in those fed the lipid-adequate, Zn-deficient diet ad libitum (ZD group). The enzyme activity in both intestine and liver of the ZDLR group was greater than in those of the ZD group and greater than or equal to those of the ZS and PF diet groups. The results of this study suggest that the reduction in alkaline phosphatase in Zn-deficient animals is a response secondary to associated inanition.

Alkaline Phosphatase↗
PubMed1979

Possible psychopharmacological agents. Part 7: Synthesis and CNS activity of some fluorinated 2,4,7/8-trisubstituted-3H-1,5-benzodiazepinium monoperchlorates.

A series of new fluorinated 2,4'7/8-trisubstituted-3H-1,5-benzodiazepinium monoperchlorates have been synthesized and characterized by IR and NMR spectral studies. Representative compounds have been screened for their CNS activity viz., behavioural, analgesic, anticonvulsant and antireserpine. 8-Chloro-2-(4'-fluorophenyl)-4-phenyl-3H-1,5-benzodiazepinium monoperchlorate has shown pronounced antireserpine activity.

Analgesics↗
PubMedDate not supplied

Glycomimetics: a programmed approach toward neoglycopeptide libraries.

A programmed synthesis of neoglycopeptides has been developed in which two, similar or different, glycoside moieties could be attached either (i) at the N-terminal of short peptides or (ii) one at the N-internal and the other(s) at the N-terminal site, in a highly flexible and controlled manner. A stepwise branching of N-terminal peptides has been achieved by glycoside aldehyde reductive amination followed by the glycoside carboxylic acid coupling (model 1). In another approach, after N-alkylation with glycoside aldehyde, the N-glycosylated derivative is subjected to peptide synthesis. This is then followed by the attachment of the second glycoside moiety at the N-terminal using either glycoside aldehyde or glycoside carboxylic acid derivative (model 2). Alternatively, the attachment of second and third glycoside derivatives could be achieved simultaneously, by reductive amination/carboxylic acid couplings (model 3). The methodologies presented here are highly versatile and combine diversity in both peptides/pseudopeptides and glycoside moieties.

Carbohydrate Sequence↗