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Biomedical subjects

P Patel

Publications and source records attributed to P Patel.

At least 37 records · Page 2Linked to original sources
PubMed2004

Management of Mersilene mesh chronic eyelid complications: a systematic approach.

BACKGROUND: Mersilene mesh (polyester fibre) is commonly used in ptosis surgery for frontalis suspension as it is readily available and cheap. Management of extrusion can be challenging. We report three cases of extrusion where extremely thick mesh or extremely thin tissue may have contributed to the extrusion. METHODS: Retrospective case note study of three adult patients who developed chronic mesh extrusion. RESULTS: Extrusion and chronic infection occurred 5-12 months after surgery. Despite systemic antibiotics, all three patients required surgical excision of mesh from the eyelid up to the brow, which was curative. CONCLUSION: These cases illustrate the need for a systematic approach and the need in some cases to excise the mesh to prevent recurrent infection.

Aged↗
PubMed2004

Caloric restriction and body weight independently affect longevity in Wistar rats.

OBJECTIVE: To evaluate the independent effects of caloric restriction (CR) and body weight (BW) on mortality rate (MR) and the extent to which BW may mediate the effect of CR on MR. DESIGN AND SUBJECTS: Data were from the Biosure Study, a randomized, controlled, prospective intervention study of diet regimens in 1200 Wistar rats. Animals were followed until they died spontaneously, were euthanized because of illness, or reached age 30 months. STATISTICAL ANALYSIS: Cox regression was performed to evaluate the effects of CR and BW on MR. Bootstrap procedures were used to test the contribution of BW to the effect of CR on MR. RESULTS: CR initiated after age 13 weeks decreased the rate of subsequent mortality. The MR increased with higher BW in early adulthood (21 weeks) and this effect persisted even after adjustment for CR. After adjustment for BW in early adulthood, we did not find a similar relation between mortality and BW in late adulthood (105 weeks). Mediation analysis indicated that low BW associated with CR appeared to mediate some of the mortality-reducing effects of CR, but CR clearly had effects independent of BW. The reductions in BW appeared to account for approximately 11% of the effect of CR. CONCLUSION: CR and BW have independent effects on MR in Wistar rats. BW may mediate a small part of the CR effects on MR.

Aging↗
PubMed2004

Is gene therapy the answer for prostate cancer?

Prostate cancer is the third most common cancer, accounting for one in 10 cancer diagnoses in men worldwide during 2000. Despite this high burden of morbidity, there is a lack of curative treatments for locally advanced and metastatic disease. Good anatomical accessibility of the prostate combined with substantial molecular understanding of the disease makes prostate cancer an attractive target for gene therapy. Considerable progress has been made in the development of suitable gene transfer vectors and prostate-targeting strategies. Therapeutic approaches being explored fall into two broad categories: corrective and cytoreductive/cytolytic. There are currently 63 prostate cancer gene therapy clinical trials based on these approaches registered in the United States and United Kingdom. Although significant hurdles remain to be overcome, early clinical trial results are encouraging, suggesting that gene therapy may become an important treatment option for prostate cancer.

Clinical Trials as Topic↗
PubMed2004

Audit of neurosurgery senior house officer training in the United Kingdom and Eire: a postal survey.

An audit was performed to describe the current training conditions of senior house officers in neurosurgery in the UK and Eire. A postal questionnaire was sent to all neurosurgery senior house officers in a 6-month training period between February and August 2003. The questionnaire covered most aspects of working pattern, training and job satisfaction by the end of the 6-month post. The results from the audit showed that there are deficiencies in certain areas of the current system being employed for senior house officer training. Improvements to this training system in line with the establishment of a generic neurosciences training programme will benefit future surgical trainees.

Education, Medical, Continuing↗
PubMed2004

Prophylactic management of children at risk for recurrent upper respiratory infections: the Preventia I Study.

BACKGROUND: Given the morbidity and mortality of asthma and the recent dramatic increase in its prevalence, pharmacologic prophylaxis of this disease in children at risk would represent a major medical advance. OBJECTIVES: The Preventia I Study was designed to evaluate the efficacy and long-term safety of loratadine in reducing the number of respiratory infections in children at 24 months. A secondary objective was to investigate the benefit of loratadine treatment in preventing the onset of respiratory exacerbations. METHODS: Preventia I was a randomized placebo-controlled study involving 22 countries worldwide. The children were 12-30 months of age at enrollment and had experienced at least five episodes of ENT infections, and no more than two episodes of wheezing during the previous 12 months. Phase I was a 12-month double-blind period during which the children were treated with loratadine 5 mg/day (2.5 mg/day for children</=24 months of age) or placebo. Phase II was a double-blind follow-up period without study medication. RESULTS: Of the 412 children enrolled, 342 and 310 completed Phase I and Phase II, respectively. The results showed a significant decrease in the number of infections in the whole population of children. However, no difference was observed between the loratadine and placebo group. When considering secondary end-points, loratadine was shown to reduce the number of respiratory exacerbations during the treatment phase. None of the 204 children who received loratadine discontinued the study because of drug-related events. Loratadine treatment was not more sedative than placebo and was not associated with cardiovascular events. CONCLUSION: The strong decrease in the rate of infections in the children at risk of recurrent infections, while not being influenced by loratadine treatment, should encourage future reflection in terms of prophylactic management. This study also confirms the long-term safety of loratadine and its metabolites in young children.

Anti-Allergic Agents↗
PubMed2004

Functional results and complications of Mersilene mesh use for frontalis suspension ptosis surgery.

AIMS: To assess the functional results and complications of Mersilene (polyester) mesh frontalis sling suspension to correct poor levator function ptosis. METHODS: Retrospective case series. 32 eyelids of 20 patients (12 children and eight adults). RESULTS: Follow up 1-69 months (mean 32). CHILDREN: eight patients had bilateral and four unilateral surgery (20 eyelids). Good long term functional results were achieved in 73% (8/11 children) and 77% (14/18) eyelids. Two children had early postoperative wound infection requiring removal of mesh in one; the other was lost to follow up following medical treatment. ADULTS: four patients had bilateral and four unilateral surgery (12 eyelids). Good long term functional results were achieved in 75% (6/8 patients, 9/12 eyelids). One postoperative wound infection and one mesh exposure were treated definitively by surgical excision of mesh. CONCLUSION: Mersilene mesh provides good functional results but up to 20% of patients have early soft tissue complications. Other materials such as monofilament suture or autogenous fascia lata should be considered.

Adolescent↗
PubMed2004

A comparative clarithromycin bioavailability study: determination of clarithromycin and 14-(R)-hydroxyclarithromycin under fasting and fed conditions.

OBJECTIVE: To report the first comprehensive analysis of clarithromycin (CLA) and 14-(R)-hydroxyclarithromcin (14R) bioequivalence metrics under both fasting and fed conditions when using a validated analytical method. METHODS AND MATERIALS: In separate, single dose bioequivalence studies, fasting (n = 40) and fed (n = 18) non-smoking subjects entered a 2-treatment, 2-period, 2-sequence, crossover trial to assess the comparative bioavailability of a 500 mg generic clarithromycin tablet (IVAX Pharmaceuticals, NJ, USA) relative to the reference product (Biaxin Filmtab, Abbott Laboratories, IL, USA). The validated assay employed an HPLC coupled to a triple stage quadrupole mass spectrometer. RESULTS: The analytics permitted plasma samples to be measured for both analytes with high precision and a lower limit ofquantitation (LLOQ) of 11 ng/ml. In both fasting and fed studies, and for both analytes, the IVAX product met the common mean geometric ratio and 90% confidence limits in order to be declared bioequivalent with Biaxin Filmtab. Furthermore, the intra-subject variabilities for the comparative AUC metrics in both studies and for both analytes were < or = 21% and < or = 26% for Cmax. CONCLUSIONS: The fasting and fed results present definitive evidence that 500 mg IVAX clarithromycin and Biaxin Filmtab are bioequivalent under both fasting and fed conditions, whether based on CLA or 14R. Furthermore, at a 500 mg dose, clarithromycin is not a highly variable drug.

Administration, Oral↗
PubMed2003

Vascular and metabolic response to isolated small muscle mass exercise: effect of age.

To determine the effect of age on quadriceps muscle blood flow (QMBF), leg vascular resistance (LVR), and maximum oxygen uptake (QVO2 max), a thermal dilution technique was used in conjunction with arterial and venous femoral blood sampling in six sedentary young (19.8 +/- 1.3 yr) and six sedentary old (66.5 +/- 2.1 yr) males during incremental knee extensor exercise (KE). Young and old attained a similar maximal KE work rate (WRmax) (young: 25.2 +/- 2.1 and old: 24.1 +/- 4 W) and QVO2 max (young: 0.52 +/- 0.03 and old: 0.42 +/- 0.05 l/min). QMBF during KE was lower in old subjects by approximately 500 ml/min across all work rates, with old subjects demonstrating a significantly lower QMBF/W (old: 174 +/- 20 and young: 239 +/- 46 ml. min-1. W-1). Although the vasodilatory response to incremental KE was approximately 142% greater in the old (young: 0.0019 and old: 0.0046 mmHg. min. ml-1. W-1), consistently elevated leg vascular resistance (LVR) in the old, approximately 80% higher LVR in the old at 50% WR and approximately 40% higher LVR in the old at WRmax (young: 44.1 +/- 3.6 and old: 31.0 +/- 1.7 mmHg. min. ml-1), dictated that during incremental KE the LVR of the old subjects was never less than that of the young subjects. Pulse pressures, indicative of arterial vessel compliance, were approximately 36% higher in the old subjects across all work rates. In conclusion, well-matched sedentary young and old subjects with similar quadriceps muscle mass achieved a similar WRmax and QVO2 max during incremental KE. The old subjects, despite a reduced QMBF, had a greater vasodilatory response to incremental KE. Given that small muscle mass exercise, such as KE, utilizes only a fraction of maximal cardiac output, peripheral mechanisms such as consistently elevated leg vascular resistance and greater pulse pressures appear to be responsible for reduced blood flow persisting throughout graded KE in the old subjects.

Adolescent↗
PubMed2003

Semi quantitative expression analysis of MDR3, FIC1, BSEP, OATP-A, OATP-C,OATP-D, OATP-E and NTCP gene transcripts in 1st and 3rd trimester human placenta.

Using real time RT-PCR, we have detected expression of seven genes that influence bile acid transport,MDR3, FIC1, BSEP, OATP-A, OATP-C, OATP-D and OATP-E, in normal human placenta. With the exception of OATP-C and OATP-E these genes were found to be differentially expressed in 1st trimester and 3rd trimester placentae. MDR3 gene expression was found to be up regulated four fold in 3rd trimester placentae compared to 1st trimester, OATP-A gene expression was down regulated eight fold, OATP-D was down regulated 17 fold, while FIC1 expression was reduced by 33 fold in the 3rd trimester. OATP-C and BSEP gene expression was not detected in the 3rd trimester placenta, while low levels of transcripts were detected in the 1st trimester placentae. Transcripts of the hepatic sinusoidal bile acid transporter, NTCP, were not detected in placenta.

ATP Binding Cassette Transporter, Subfamily B↗
PubMed2003

Cost-effectiveness of population screening for Helicobacter pylori in preventing gastric cancer and peptic ulcer disease, using simulation.

OBJECTIVES: To evaluate the cost-effectiveness of population screening for Helicobacter pylori in preventing gastric cancer and peptic ulcer disease in England and Wales. METHODS: A discrete event simulation model used parameter estimates, derived from peer-reviewed literature, routine data and statistical modelling. Population screening was compared with no screening but with opportunistic eradication in patients presenting with dyspepsia. Costs included screening, eradication and costs averted to provide costs per life years saved (cost/LYS) for preventing gastric cancer and peptic ulcer disease. Sensitivity analyses were undertaken. RESULTS: The cost/LYS from screening at age 40 years was Uk pounds 5860 at discount rates of 6%. The outcomes were sensitive to H. pylori prevalence, the degree of opportunistic eradication, the discount rate, the efficacy of eradication on gastric cancer risk, the risk of complicated peptic ulcer disease and gastric cancer associated with H. pylori infection, and the duration of follow-up. In sensitivity analyses, the cost/LYS rarely exceeded UK pounds 20000 over an 80-year follow-up, but did for shorter periods. CONCLUSIONS: H. pylori screening may be cost-effective in the long term. However, before screening can be recommended further evidence is needed to resolve some of the uncertainties, particularly over the efficacy of eradication on risk of gastric cancer, the risk associated with complicated peptic ulcers, and the effect of more widespread opportunistic testing of patients with dyspepsia.

Adult↗
PubMed2003

Protection against methacholine-induced bronchospasm: salbutamol pMDI versus Clickhaler DPI.

Passive dry-powder inhalers (DPIs) have been developed as an alternative to pressurised metered-dose inhalers (pMDIs) to improve aerosol delivery on inhalation and eliminate the need for propellants. However, new DPI formulations of generic drugs must be rigorously compared with conventional pMDI therapy. This randomised, double-blind, double-dummy, placebo-controlled, seven-way crossover study evaluated bronchoprotection from methacholine challenge in order to compare a novel salbutamol DPI (Clickhaler) with a reference salbutamol pMDI (Ventolin). Adult asthma patients with airway hyperresponsiveness to methacholine (provocative concentration of methacholine causing a 20% fall in the forced expiratory volume in one second (PC20) <4 mg x mL(-1)) were treated on separate days with 0, 100, 200 or 400 microg of salbutamol via the DPI or pMDI. Methacholine challenge was performed before and after salbutamol treatment and the PC20 ratios analysed by Finney's bioassay to test for therapeutic equivalence of the inhalers. Eighteen patients completed the study and showed significant dose-related responses to salbutamol. The relative potency of DPI:pMDI was 1.29 (90% confidence interval 1.04-1.63). There were no treatment differences in safety (cardiac frequency, blood pressure, adverse events). Methacholine-challenge methodology provides a sensitive bioassay and has demonstrated therapeutic equivalence of the salbutamol Clickhaler dry-powder inhaler with the conventional salbutamol pressurised metered-dose inhaler.

Adolescent↗
PubMed2003

Laser pediatric crowns performed without anesthesia: a contemporary technique.

Extensive caries resulting in the need for a stainless steel crown in primary teeth may now be prepared with the use of the WaterlaseTM YSGG Laser, (Biolase) hard and soft-tissue laser. The use of the laser eliminates the need for local anesthesia, thereby providing optimal patient comfort and compliance.

Anesthesia, Dental↗
PubMed2002

Ongoing developments in CCP4 for high-throughput structure determination.

Collaborative Computational Project Number 4 (CCP4) was established in 1979 to promote collaboration between UK groups writing software for protein crystallography. From these beginnings, CCP4 now distributes a large software suite and is active in developing new software. In this article, an overview is given of recent and ongoing developments in the CCP4 software suite, in particular as they pertain to high-throughput studies. Developments in individual programs are discussed first, although these are covered in more detail elsewhere. The bulk of the article focuses on the infrastructure of the software suite which allows the user to move effortlessly between different programs or to create automated schemas. Major changes to the software library at the heart of the CCP4 suite, developments in the CCP4 graphical user interface, and data management within CCP4 are discussed. The latter is crucial to high-throughput studies, where a large number of data are imported, created and finally archived.

Crystallography, X-Ray↗
PubMed2002

Chemo-ablation of the prostate with dehydrated alcohol for the treatment of prostatic obstruction.

PURPOSE: We confirmed clinically whether chemo-ablation of the prostate with absolute ethanol may be an innovative transurethral approach for the relief of obstructive benign prostatic hyperplasia. METHODS: Using the InjecTx endoscopic device (Injectx Inc., San Jose, California) an initial cohort of 15 patients, including 13 who have now been followed more than 1 year, underwent elective transurethral chemo-ablation of the prostate. RESULTS: Preoperative and postoperative comparisons of the American Urological Association symptom score, maximum urine flow rate and prostatic volume reveal significant improvement with minimal discomfort and no major complication. CONCLUSIONS: The InjecTx technique proved encouragingly successful in this initial small-scale clinical trial.

Aged↗
PubMed2001

Synthesis and microtubule binding of fluorescent paclitaxel derivatives.

The preparation of two new fluorescent derivatives of paclitaxel in which the fluorophore is bonded to paclitaxel at the C-10 position is reported. Both analogues, 10-deacetyl-10-(m-aminobenzoyl)paclitaxel (1, BTax) and 10-deacetyl-10-[7-(diethylamino) coumarin-3-carbonyl]paclitaxel (2, CTax) retain good activity as promoters of in vitro tubulin assembly. Microtubule binding enhances the emission intensity of both probes.

Fluorescent Dyes↗
PubMed2001

The cytoplasmic and transmembrane domains of the p75 and Trk A receptors regulate high affinity binding to nerve growth factor.

Ligand-induced receptor oligomerization is an established mechanism for receptor-tyrosine kinase activation. However, numerous receptor-tyrosine kinases are expressed in multicomponent complexes with other receptors that may signal independently or alter the binding characteristics of the receptor-tyrosine kinase. Nerve growth factor (NGF) interacts with two structurally unrelated receptors, the Trk A receptor-tyrosine kinase and p75, a tumor necrosis factor receptor family member. Each receptor binds independently to NGF with predominantly low affinity (K(d) = 10(-9) m), but they produce high affinity binding sites (K(d) = 10(-11) m) upon receptor co-expression. Here we provide evidence that the number of high affinity sites is regulated by the ratio of the two receptors and by specific domains of Trk A and p75. Co-expression of Trk A containing mutant transmembrane or cytoplasmic domains with p75 yielded reduced numbers of high affinity binding sites. Similarly, co-expression of mutant p75 containing altered transmembrane and cytoplasmic domains with Trk A also resulted in predominantly low affinity binding sites. Surprisingly, extracellular domain mutations of p75 that abolished NGF binding still generated high affinity binding with Trk A. These results indicate that the transmembrane and cytoplasmic domains of Trk A and p75 are responsible for high affinity site formation and suggest that p75 alters the conformation of Trk A to generate high affinity NGF binding.

Animals↗