PubMed Health⌕ Search

Biomedical subjects

P Pillai

Publications and source records attributed to P Pillai.

At least 19 recordsLinked to original sources
PubMed2006

Distribution of novel and previously investigated virulence genes in colonizing and invasive isolates of Streptococcus agalactiae.

Although Streptococcus agalactiae has emerged as an important cause of invasive disease, relatively little is known regarding the genetic basis of virulence of this organism. Three novel genes with characteristics suggesting a role in virulence were identified via comparison of sequenced genomes of S. agalactiae. The presence of these genes and of the previously identified genes bac, bca, rib, and spb1 was determined, and isolates were assigned a binary genetic signature. It was found that isolates containing spb1, previously suggested to be limited to serotype III-3, were represented by 18 different genetic signatures and several serotypes, and that the presence of both sbp1 and rib was more predictive of invasive disease than spb1 alone. Additionally, bac-positive isolates, reported to be genetically homogeneous, were represented by 14 different genetic signatures. Finally, the majority of serotype V isolates examined contained zero or only one of the genes tested, suggesting that much remains undiscovered regarding important virulence factors in isolates of this serotype.

Aged↗
PubMed2006

Modelling response time profiles in the absence of drug concentrations: definition and performance evaluation of the K-PD model.

The plasma concentration-time profile of a drug is essential to explain the relationship between the administered dose and the kinetics of drug action. However, in some cases such as in pre-clinical pharmacology or phase-III clinical studies where it is not always possible to collect all the required PK information, this relationship can be difficult to establish. In these circumstances several authors have proposed simple models that can analyse and simulate the kinetics of the drug action in the absence of PK data. The present work further develops and evaluates the performance of such an approach. A virtual compartment representing the biophase in which the concentration is in equilibrium with the observed effect is used to extract the (pharmaco)kinetic component from the pharmacodynamic data alone. Parameters of this model are the elimination rate constant from the virtual compartment (KDE), which describes the equilibrium between the rate of dose administration and the observed effect, and the second parameter, named EDK(50) which is the apparent in vivo potency of the drug at steady state, analogous to the product of EC(50), the pharmacodynamic potency, and clearance, the PK "potency" at steady state. Using population simulation and subsequent (blinded) analysis to evaluate this approach, it is demonstrated that the proposed model usually performs well and can be used for predictive simulations in drug development. However, there are several important limitations to this approach. For example, the investigated doses should extend from those producing responses well below the EC(50) to those producing ones close to the maximum response, optimally reach steady state response and followed until the response returns to baseline. It is shown that large inter-individual variability on PK-PD parameters will produce biases as well as large imprecision on parameter estimates. It is also clear that extrapolations to dosage routes or schedules other than those used to estimate the parameters should be undertaken with great caution (e.g., in case of non-linearity or complex drug distribution). Consequently, it is advised to apply this approach only when the underlying structural PD and PK are well understood. In any case, K-PD model should definitively not be substituted for the gold standard PK-PD model when correct full model can and should be identified.

Adenosine↗
PubMed2005

Intra-operative diagnosis of hypopituitarism in a patient undergoing radical nephrectomy.

A 43-year-old woman presented for elective radical nephrectomy. After induction of anaesthesia, she developed hypotension that failed to respond to standard treatment measures. Her core temperature decreased to 34 degrees C in spite of active warming. She required very low concentrations of anaesthetic agents to maintain an adequate depth of anaesthesia for abdominal surgery. After excluding the common causes of hypotension, the possibility of subclinical hypopituitarism was considered and subsequently confirmed.

Adult↗
PubMed1999

Using technology to educate deaf and hard of hearing children in rural Alaskan general education settings.

Teachers in Alaskan rural schools were surveyed on their use of instructional technology. The surveyed teachers included the entire population of certified elementary and secondary school classroom teachers of deaf and hard of hearing students in these schools. Respondents generally were older, more experienced, elementary level female teachers who were relatively well educated. Almost half of the respondents held special education certification; about 25% had an endorsement in deaf education. Data analysis indicates that educators who use instructional technology, either in curriculum or broad agenda formats, may be older, hold an advanced degree and secondary education certification, benefit from in-service training on site, are connected to the Internet, and actively use the technology available at their schools. Most of the surveyed educators identified lack of training in the use and integration of software as a barrier to increased classroom use of technology. Based on the study findings, recommendations are made concerning the training needs of teachers in rural Alaska.

Alaska↗
PubMed1996

High-performance liquid chromatographic resolution of NADP+ after induction of fluorescence and its application to assay for an NADPH-dependent enzyme: application to the determination of glutathione reductase activity in plant leaf extracts.

A method is described for the determination of glutathione reductase activity (GR; EC 1.6.4.2) in plant extracts utilizing HPLC quantitation of NADP+ following the reduction of glutathione disulfides. After protein incubation, fluorescence of NADP+ was induced under strongly basic conditions, and the product was directly resolved from the reaction medium by isocratic reversed-phase elution on a silica-coated alumina support which took 2 min. The mobile phase was acetonitrile-water (50:50) delivered at a flow rate of 1.5 ml/min. The adduct (stable for at least 7 days) was detected fluorometrically and quantitated by direct integration of peak area.

Chromatography, High Pressure Liquid↗
PubMed1995

Licorice-derived compounds inhibit linoleic acid (C:18:2 omega 6) desaturation in soybean chloroplasts.

Although glycyrrhizic acid, a major constituent of licorice root, has important pharmacological effects in humans, the biological activity of glycyrrhizic acid and its aglycone glycyrrhetinic acid in plants is unknown. Here we report that these licorice-derived compounds and the analog carbenoxolone inhibit desaturation of linoleic acid (C18:2 omega 6) in soybean chloroplasts using monogalactosyldiacylglycerol and phosphatidylcholine substrates in an in vitro assay for desaturase activity. At 10 nM glycyrrhetinic acid, there is significant inhibition of desaturation of linoleic acid suggesting that licorice-derived compounds could prove useful in investigating biochemical pathways of linoleic acid desaturation in plant chloroplasts and plant desaturase regulation, which has application in modification of plant response to environmental stress, as well as optimization of oil seed composition.

Carbohydrate Sequence↗
PubMed1995

Rapid diagnosis of typhoid fever by detection of Barber protein and Vi antigen of Salmonella serotype typhi.

Co-agglutination (coagg) and latex agglutination (LA) tests were used for the detection of Salmonella serotype Typhi Vi and Barber protein (BP) antigens in sera from five groups of individuals (A-E). Group A consisted of 30 blood culture-positive cases of typhoid fever and group B consisted of 30 suspected cases of typhoid fever who had sterile blood cultures but positive Widal tests. Thirty cases of pyrexia of unknown origin (PUO) were placed in group C, while group D consisted of 15 cases of septicaemia caused by organisms other than Salmonella serotype Typhi. Group E comprised 50 normal healthy individuals with no history of typhoid fever or TAB vaccination in the previous 5 years. The Vi-LA test performed best with 96.7% of group A sera and 90% of group B sera giving positive results. No false positive results and only 2.58% false negative results were obtained with this test. Considering patients with positive blood culture results or positive Widal tests as true positives, the sensitivities of the Vi-LA, BP-LA, Vi-coagg and BP-coagg tests were 93.3, 91.7, 83.3 and 86.7%, respectively. The specificities of these tests were 100, 98.5, 98.5 and 98.5%, respectively. It is suggested that the Vi-LA test can be used for the rapid and early diagnosis of typhoid fever.

Agglutination Tests↗
PubMed1988

Scleral tuberculosis.

A rare case of scleral tuberculosis manifesting as an ulcerative scleral nodule is described. Corroborative evidence of systemic tuberculous lesions was detectable. The lesion responded to antituberculous treatment alone.

Adult↗
PubMed1988

Bilateral sino-orbital pseudotumour.

The authors present a case of histopathologically proved bilateral idiopathic inflammatory pseudotumour of the orbits with involvement of the paranasal sinuses in a child. Clinically, the bilateral proptosis was manifest at the age of 5 years. While extraorbital manifestations are rare, orbital pseudotumour should be considered in such cases.

Child, Preschool↗
PubMed1981

Lipid composition of chloroplast membranes from weed biotypes differentially sensitive to triazine herbicides.

Chloroplasts were isolated from triazine-sensitive and triazine-resistant biotypes of common groundsel (Senecio vulgaris L.), common lambsquarter (Chenopodium album L.), and redroot pigweed (Amaranthus retroflexus L.). Chloroplast lipids were extracted and analyzed for differences among sensitive and resistant biotypes. The distribution of lipid between major lipid classes differed in chloroplasts from resistant and susceptible biotypes. Chloroplasts from resistant biotypes contained higher proportions of monogalactosyl diglyceride and phosphatidyl ethanolamine and lower proportions of digalactosyl diglyceride and phosphatidyl choline than did chloroplasts from susceptible biotypes. Monogalactosyl diglyceride and phosphatidyl ethanolamine were also quantitatively higher in membranes of resistant versus susceptible biotypes. The major lipid classes of resistant chloroplast membranes contained lipids comparatively richer in unsaturated fatty acids with the exceptions of digalactosyl diglyceride from all three biotypes and phosphatidyl ethanolamine from common groundsel. Results correlated changes in triazine sensitivity with qualitative and quantitative differences in the lipid composition of chloroplast membranes.

Journal Article↗
PubMedDate not supplied

Congenital cataract: management and results.

The visual outcome in cases of congenital cataract, managed both surgically and conservatively, is outlined. Final vision was better in cases with partial cataract, about 40% of whom attained 6/24 or better vision. With total cataracts, none could achieve this level of vision, with the majority (84%) attaining only 6/60 or less acuity. Visual results were also better in patients without nystagmus, 34% of whom attained 6/24 or better vision, while in cases with nystagmus, only 15% could come up to this level. Cataracts necessitating early surgery had a worse prognosis than cataracts necessitating late surgery. Visual results were best in cases with bilateral cataracts, partial cataracts, absence of associated ocular anomalies, the absence of nystagmus and in patients requiring later surgery. The important causes of nonimprovement of vision were amblyopia and after-cataract. Retinal detachment, retinopathy, and degenerative myopia were some of the less frequent causes of poor vision, while mental retardation was another important factor. Full cooperation from the parents is absolutely essential in the proper visual rehabilitation of the handicapped child.

Age Factors↗
PubMedDate not supplied

Cyclic esotropia with central nervous system disease: report of two cases.

Two cases of cyclic esotropia with associated central nervous system lesions are presented. One had a 48-hour cycle and the other a 24-hour cycle. In the first child, the condition developed after a third ventricular astrocytoma removal and in the second with the advent of an epileptiform disorder. Both were non-accommodative, non-paralytic in nature, and not associated with fusion disrupting factors. These patterns persisted uninterruptedly in one child for 22 months and in the other for more than 8 months until lost for follow-up.

Astrocytoma↗
PubMedDate not supplied

Assessment of depression in older people.

Practitioners working in the field of mental health are becoming increasingly aware that depression and suicide in old age are a major source of concern. Peter Pillai continues the series of articles on aspects of mental health assessment co-ordinated by the RCN Steering Committee for Mental Health and Older People which explores the nurse's role in assessing depression in this particular client group.

Aged↗