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Biomedical subjects

P Nair

Publications and source records attributed to P Nair.

At least 19 recordsLinked to original sources
PubMed2006

Statins and the acute coronary syndrome: 'the early bird catches the worm'.

The early period following an acute coronary syndrome (ACS) is characterised by atherosclerotic plaque destabilisation and a pro-coagulant state, and is when patients are at highest risk for recurrent cardiovascular events and mortality. Statins decrease thrombus formation and increase fibrinolysis, inhibit platelet reactivity and aggregation, improve endothelial function in patients with coronary artery disease and have a major role in plaque stabilisation. Several studies showed that initiation of early statin therapy in these settings may have beneficial effects. This review summarises the current data on statins in the setting of ACSs. Known and other possible mechanisms of action are described. The pathophysiological mechanisms, histological features and biochemical characteristics of ACS are different than those with stable coronary disease, thereby suggesting that the mechanisms whereby statins exert their benefits in ACS may be distinct from those for stable CHD. Initiation of the therapy during hospitalisation rather than at the time of hospital discharge may provide protection against early recurrent cardiovascular events and also improve patients' compliance.

C-Reactive Protein↗
PubMed2004

Public health management of a suspected case of rabies.

A female nurse, recruited from the Philippines five months previously, developed meningo-encephalitis and was hospitalised. She was later transferred to a hospital in a neighbouring region for specialist treatment. Rabies was part of a differential diagnosis and decisions on public health intervention had to be made in the absence of a firm diagnosis or clinical history. These decisions centred on what infection control measures should be put into effect and when. Issues included the leadership and composition of the incident management team, the coordination of consistent approaches between the health regions and organisations involved, the different priorities of those forming the team and, in particular, contacts with the media and meeting public anxieties.

Animals↗
PubMed2003

Gingival bleeding on probing increases after quitting smoking.

BACKGROUND: Gingival inflammation associated with plaque accumulation is delayed or impaired in smokers. Anecdotal evidence suggests that smokers who quit experience an increase in gingival bleeding. METHOD: A group of 27 subjects on a Quit-smoking programme were examined for changes in gingival health over a 4-6-week period. RESULTS: The bleeding on probing with a constant force probe increased from 16% of sites to 32% of sites, despite improvements in the subjects oral hygiene. CONCLUSION: This provides further evidence that tobacco smoking affects the inflammatory response and that these changes are reversible on quitting.

Adult↗
PubMed2003

One-stop clinic for postmenopausal bleeding at district general hospital: does it have a role?

A postmenopausal bleeding (PMB) clinic was set up to provide quicker access for consultation, transvaginal ultrasound (TVS) and pipelle endometrial sampling in one visit. The aim of the study was to evaluate the impact of a one-stop PMB clinic on reaching a diagnosis and initiating treatment. One hundred and seven women have been referred to PMB clinic since the service started. We analysed the prospective findings of 80 patients who met the criteria of direct GP referral to PMB clinic. The mean time from GP referral to consultation at PMB clinic was 14.8 days (range: 2-24 days); 97.5% of women had TVS and abnormal findings were reported in 67.5%. Pipelle endometrial sampling was performed in 31 patients and a sample obtained successfully in 21 women. Ten women were referred directly for diagnostic hysteroscopy and another 10 had hysteroscopy after a failed pipelle sampling. Twenty-four women (30%) were discharged back to their general practitioners (GPs) after reassurance by consultation and normal TVS. Seventy women (87.5%) considered a single PMB clinic visit was satisfactory. This study demonstrates the effective role of the one-stop PMB clinic to provide quick reassurance, arrive at a diagnosis and initiate plan of management during a single outpatient visit.

Aged↗
PubMed2003

How long can donor sclera be safely stored?

PURPOSE: To determine whether after prolonged storage of sclera in glycerin, there is any bacteriologic contamination that will reactivate, whether reconstituted sclera retains its tensile strength, and whether sclera retains its microstructural integrity. METHODS: Sixty-six scleral shells stored in glycerin for 9 to 19 years, as well as 11 controls stored for 6 months to 4 years, were studied by cutting a small wedge of tissue from the anterior margin of each and directly inoculating into thioglycolate broth, cutting an equatorial ring and determining its break strength using a tensiometer, and cutting a small piece from the remaining posterior portion and examining by scanning electron microscopy. RESULTS: After such prolonged storage, bacteriologic contamination was not detected, tensile strength generally increased with increasing duration of storage, and ultrastructural integrity was maintained on scanning electron microscopy. CONCLUSIONS: This study suggests that storage of scleral shells can be safely prolonged; we hope this can facilitate an increased supply of donated sclera to patients and surgeons.

Bacteria↗
PubMed2002

Does Helicobacter pylori eradication reduce the long-term requirements for acid suppressants in patients with a history of peptic ulcer disease in general practice? Results from a four-year longitudinal study.

BACKGROUND: Acid suppressants, especially proton-pump inhibitors, are major contributors to the drug costs in primary care. Although Helicobacter pylori eradication reduces peptic ulcer relapse, some studies suggest that patients may remain symptomatic and continue to require acid-suppressant therapy. METHODS: We identified all patients taking long-term acid suppressants in a large primary health care clinic to determine the proportion who had peptic ulcer disease and to examine the effect of H. pylori eradication on their long-term requirement for acid suppressants. RESULTS: 126/394 patients taking long-term acid suppressants had a definite diagnosis of peptic ulcer. Of these 126 patients, 60 were considered appropriate for the study. At Stage 1 (May 1994), all patients were tested for H. pylori infection and positive patients (60/66) received eradication therapy with omeprazole 20 mg bd and amoxycillin (1 gm bd) or clarithromycin (500 mg tds) for 2 weeks. Six weeks later (Stage 2) patients, requirements for continued acid-suppressant treatment were determined and previously positive subjects retested using the 13C urea breath rest. This showed that 70% (42/60) had been successfully eradicated. One year later (Stage 3), 44% (18/41) of the patients successfully eradicated still required acid suppressants. The majority of these patients (11/18; 61%) continued to remain on acid-suppressant treatment at 4 years (Stage 4) (95% CI 38%, 83%). CONCLUSIONS: We found that about 1/3 of all patients on long-term acid-suppressant therapy in General Practice had a confirmed diagnosis of peptic ulcer disease. Despite successful eradication treatment for H. pylori at the start of the study, about half of these patients still used acid suppressants after 1 year and 1/4 patients (11/41) in this group continued to remain on acid-suppressant treatment for another 3 years.

Amoxicillin↗
PubMed2002

Relationship between the birth cohort pattern of Helicobacter pylori infection and the epidemiology of duodenal ulcer.

BACKGROUND: Helicobacter-pylori-related duodenal ulcer (DU) is an important cause of dyspepsia. AIM: To determine the relationship between the pattern of H. pylori infection and the epidemiology of duodenal ulcer in a single population. DESIGN: Prospective two-part study of (i) patients with DU referred for endoscopy because of dyspepsia, and (ii) the incidence of H. pylori infection in the general population of the same area. METHODS: Details of 533 DU patients were recorded, and related to the pattern of H. pylori infection among 10 537 adults in the same community, determined by the (13)C-urea breath test. RESULTS: In patients with DU, birth year was more important than age in determining the rate of presentation for endoscopy (the 'birth cohort' effect). H. pylori infection showed a similar birth cohort effect, and the prevalence decreased steadily in those born in successive years, from 28.8% in the 1930s to 3.5% in the 1970s. The proportion of dyspeptic patients who had duodenal ulcers also fell progressively, from 22.2% in 1979 to 5.7% in 1998. H. pylori prevalence and duodenal ulcer incidence were closely correlated at all ages. DISCUSSION: Duodenal ulcer prevalence (as judged by the rate of referral of duodenal ulcer patients for endoscopy) is determined principally by the distribution of H. pylori infection in the local population. The birth cohort effect seen in adult duodenal ulcer patients reflects the acquisition of H. pylori in childhood. In Bristol, H. pylori prevalence and duodenal ulcer incidence are both declining to very low levels.

Adult↗
PubMed2001

Witnessing violence among inner-city children of substance-abusing and non-substance-abusing women.

OBJECTIVES: To determine if children of substance-abusing mothers witness more violence than children of non-substance-abusing (control) mothers, and to determine if children who witness violence have more behavioral problems and higher stress scores than children who do not witness violence. DESIGN: Cross-sectional research design comparing exposure to violence among children of substance-abusing mothers and control mothers of low socioeconomic status. SETTING: An inner-city pediatric clinic. PARTICIPANTS: Forty substance-abusing mothers and their children, and 40 non-substance-abusing mothers and their children, examined when the children were 6 years old. MAIN OUTCOME MEASURES: Maternal report of children's exposure to violence was assessed using the Exposure to Violence Interview and the Conflict Tactics Scale. Maternal report of children's behavior was assessed using the Child Behavior Checklist and the Children's Response to Stress Inventory. RESULTS: Children of substance-abusing mothers did not witness more violence than the control children (P>.05). However, 6-year-old inner-city children in the present study witnessed a high rate of violence: 43% had seen someone beaten up, 13% had seen someone threatened with a knife, and 7% had seen someone stabbed or shot. Children witnessing violence had significantly higher aggressive, delinquent, anxious/depressed, withdrawn, attention, and social problems (P<.05) on the Child Behavior Checklist, and higher stress scores (P =.05) on the Children's Response to Stress Inventory. CONCLUSIONS: More than half of the 6-year-old inner-city children in the present study witnessed some form of violence. Witnessing violence was associated with more behavioral problems and higher stress scores as assessed through maternal report. Subsequent research should examine the long-term effects of this exposure to violence among young children.

Adult↗
PubMed2001

Age-dependent variation in contractility of adult cardiac myocytes.

This study was designed to examine the influence of the age of adults on the contractile characteristics of the myocardium and to ascertain whether the age dependent variation is related to variation in sarcolemmal calcium channels. Cardiomyocytes were isolated from 2, 6 and 12-month-old, male Sprague-Dawley rats and the extent and velocity of contraction were recorded as a function of change in cell length. Age dependent increase in cell length and sarcomere length was significant (P<0.05). Extent of contraction increased with age and the velocities of contraction and relaxation normalized to total contraction decreased with age (P<0.05). Sensitivity to the L-type channel antagonist (verapamil, 1 microM) and the T-type channel antagonist (nickel chloride, 40 microM) was significant in 6 and 12-month-old animals. This differential response to calcium channel antagonists suggests that the age-dependent variation in contractility may be mediated by the variation in the distribution/function of sarcolemmal calcium channels.

Aging↗
PubMed2000

Ceramide selectively inhibits apoptosis-associated events in NGF-deprived sympathetic neurons.

Ceramide manifests both neurotoxic and neuroprotective properties depending on the experimental system. Ito and Horigome previously reported that ceramide delays apoptosis in a classic model of developmental programmed cell death, i.e. sympathetic neurons undergoing NGF deprivation.1 Here, we investigated the actions of ceramide upon the biochemical and genetic changes that occur in NGF deprived neurons. We correlate ceramide's neuroprotective actions with the ability of ceramide to antagonize NGF deprivation-induced oxidative stress and c-jun induction, both of which contribute to apoptosis in this model. However, ceramide did not block NGF deprivation-induced declines in RNA and protein synthesis, suggesting that ceramide does not slow all apoptosis-related events. Overall, these results are significant in that they show that ceramide acts early in the death cascade to antagonize two events necessary for NGF-deprivation induced neuronal apoptosis. Moreover, these results dissociate declines in neuronal function, i.e. macromolecular synthesis, from the neuronal death cascade.

Animals↗
PubMed2000

Telomerase, p53 and human papillomavirus infection in the uterine cervix.

Human papillomavirus infection is postulated to be a major risk factor for cervical cancer, while more recent data have stressed the clinical significance of telomerase expression during tumorigenesis. This study therefore looked for any relationship between telomerase expression, presence of human papillomavirus (HPV) and expression of the high-risk HPV E6 protein at various phases of tumor progression in the uterine cervix. In addition, accumulation of the p53 protein and total tissue proliferative fraction were also studied. Telomerase was detected using a modified TRAP (telomerase repeat amplification protocol) assay. Expression of p53, Ki 67 and E6 protein was evaluated by immunocytochemistry. Presence of mutant p53 was detected using a mutant-specific ELISA. Type of HPV infection was determined by polymerase chain reaction and Southern blot using type-specific primers and probes. There was a significant correlation between the expression of telomerase with histological grade (r = 0.646, p = 0.00003). Fisher's exact test analysis revealed that the odds ratio of a tissue sample expressing telomerase being a case (high-grade squamous intraepithelial lesion or invasive cancer) was 28.93 (p = 0.0001, 95% CI: 7.22, to 115.94). High-risk HPV-infected tissues and those expressing E6 showed increased telomerase expression (r = 0.555, p = 0.00001). Similarly, accumulation of p53 protein and increased cell proliferation (Ki 67 index) also correlated to the presence of telomerase (r = 0.661, p = 0.000004 for p53 and r = 0.647, p = 0.000003 for Ki 67). There was no correlation between telomerase expression and presence of p53 mutation. Activation of telomerase thus appears to be associated with high-risk-HPV infection, accumulation of inactive p53 protein and increased cell proliferation in cervical lesions.

Adult↗
PubMed2000

Exposure to environmental risk factors and parenting attitudes among substance-abusing women.

This study examined the amount of exposure to negative environmental risks and their association with parenting attitudes among a group of inner city substance-abusing women. Mothers (N = 198) were recruited at delivery and were part of a randomized longitudinal intervention study for substance-abusing women and their infants. When the infants were 18 months old, a cumulative environmental risk score was calculated for each mother based on nine factors: violence (both domestic and environmental), depression, homelessness, incarceration, number of children, life stress, psychiatric problems, and absence of significant other. Based on their cumulative scores, mothers were placed in a low (N = 106) or high environmental risk group (N = 92). Mothers in the high-risk group had fewer years of education and were younger when their first child was born. Multivariate analyses indicate that mothers in the high-risk group had significantly worse scores on parenting attitude scales. Given the current state of welfare reform, it is important to determine which factors besides maternal substance abuse place these mothers at risk for poor parenting.

Attitude↗
PubMed2000

Mother-infant interaction: effects of a home intervention and ongoing maternal drug use.

Examined the effects of a home-based intervention on mother-infant interaction among drug-using women and their infants. At 2 weeks postpartum, mothers and infants were randomly assigned to either an intervention (n = 84) or a control (n = 87) group. Control families received brief monthly tracking visits, and intervention families received weekly visits by trained lay visitors. Mother-infant interaction was evaluated at 6 months through observation of feeding. Although there were no direct effects of the intervention, in the control group, mothers who continued to use drugs were less responsive to their babies than mothers who were drug free. In the intervention group, drug use was not associated with maternal responsiveness. Weekly home-based intervention may be a protective strategy for children of drug-using women because it disrupts the relation between ongoing maternal drug use and low maternal responsiveness.

Adult↗
PubMed2000

Alteration in cardiomyocyte mechanics by suboptimal levels of extracellular magnesium.

The beneficial effects of magnesium supplementation in pathological situations is well known, but the myocardial response to a nominal decrease in the level of magnesium has received relatively little attention. Hypomagnesemia can occur as chronic or acute manifestation of physiological changes, pathological conditions, or pharmacological interventions. Experimental interest was focused on the mechanical changes in adult rat heart myocytes following variation in extracellular Mg2+. Isolated cells were exposed to different levels of extracellular Mg2+ and the amplitude and rate of contraction were measured as a function of change in cell length using a video-based edge-detection system. Investigations have revealed that variation in the level of Mg2+ within physiological limits leads to mechanical changes. A decrease in the level of extracellular Mg2+ was accompanied by a significant increase in contractile amplitude and decrease in the velocities of contraction and relaxation. The contractile amplitude measured as percentage shortening were 3.08+/-0.19%, 4.62+/-0.19% and 6.9+/-0.40%, respectively, on exposure to 1.8, 0.8, and 0.48 mM Mg, and the corresponding velocities of contraction and relaxation normalized to amplitude were 0.54+/-0.02, 0.40+/-0.03, 0.31+/-0.03 and 0.47+/-0.02, 0.35+/-0.02, 0.24+/-0.02. The variations in contractile parameters associated with the change in the level of Mg were statistically significant (p < 0.01). Variation in the contractile properties associated with change in extracellular Mg2+ may be effected by alteration in Ca2+ transients.

Animals↗