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Biomedical subjects

N Patel

Publications and source records attributed to N Patel.

At least 55 records · Page 3Linked to original sources
PubMed2004

Ovarian cancer detected non-invasively by contrast-enhanced power Doppler ultrasound.

Overall, about one-third of women operated upon because of suspected ovarian cancer turn out to have benign disease. This proportion will be even higher when the tumours are small. A more accurate method of determining which are malignant would reduce the number of unnecessary referrals to the cancer centre and increase the scope for conservative management. This pilot study of ultrasound and intravenous microbubble contrast in 20 women with small ovarian tumours enabled the identification of all four malignant lesions with good inter-observer agreement. These preliminary findings suggest that intravenous contrast improves the ultrasound identification of small ovarian malignancies and may provide an accurate way of selecting women who require to be referred urgently for surgery under the auspices of a gynaecological oncologist. The remainder might be considered for laparoscopic surgery or even for observation in some cases.

Adult↗
PubMed2004

Fatigue and primary biliary cirrhosis: association of globus pallidus magnetisation transfer ratio measurements with fatigue severity and blood manganese levels.

BACKGROUND AND AIM: Fatigue is the commonest symptom in primary biliary cirrhosis (PBC), affecting individuals at all stages of disease. The pathogenesis of fatigue in PBC is unknown although rat models suggest a central nervous system (CNS) cause. We examined the hypothesis that a CNS abnormality related to cholestasis, rather than cirrhosis per se, underlies this symptom. PATIENTS AND METHODS: Fourteen patients with precirrhotic PBC (stage I-II disease), four patients with stage III-IV PBC, and 11 healthy women were studied using cerebral magnetisation contrast imaging and proton magnetic resonance spectroscopy (MRS). RESULTS: The globus pallidus magnetisation transfer ratio (MTR), a quantifiable tissue characteristic that may be abnormal in the presence of normal magnetic resonance imaging, was significantly reduced in precirrhotic PBC patients compared with healthy controls. These measurements correlated with blood manganese levels and were more abnormal in the more fatigued subjects. There were no differences in MRS measurements between the three study groups, suggesting that the abnormal MTR was not related to hepatic encephalopathy. CONCLUSION: This study suggests that impairments in liver function in PBC may adversely affect the brain long before the development of cirrhosis and hepatic encephalopathy, possibly as a result of altered manganese homeostasis within the CNS.

Adult↗
PubMed2004

The safety and effectiveness of a nurse led cardioversion service under sedation.

OBJECTIVE: To assess the safety and effectiveness of nurse led elective cardioversion of atrial fibrillation under sedation. DESIGN: Prospective, longitudinal study. SETTING: Cardiac catheterisation laboratory and recovery area of a district general hospital. PATIENTS: 300 patients referred for elective cardioversion of persistent atrial fibrillation. INTERVENTIONS: Pre-procedure evaluations (history, physical examination, blood tests), consent, sedation administration, cardioversions, and post-procedure monitoring until discharge by advanced life support certified coronary care unit nurses trained in the techniques. A doctor was immediately available if required but not present. MAIN OUTCOME MEASURES: Success rates at discharge and at six weeks, energy delivered, number of shocks, dose of sedation, immediate, 24, and 48 hour patient perceptions, complications, waiting times, and cost effectiveness. RESULTS: Cardioversion success rate was 87% at discharge and 48% at six weeks. Mean (SD) cumulative energy was 497 (282) J and number of shocks 1.6 (0.8). Mean (SD) dose of sedation was 23 (9) mg intravenous diazepam. No patient required reversal of sedation, airway support, or medical intervention. Ninety eight per cent of patients had no pain or recall of the procedure. Four patients who were adequately anticoagulated experienced embolic phenomena. Ninety eight per cent of patients would repeat the procedure if necessary. Without requirement for a physician or anaesthetist, waiting times for elective cardioversion fell from three months to under four weeks. There was a significant reduction in the estimated cost of the procedure from 337 pounds sterling with general anaesthesia to 130 pounds sterling with nurse led sedation and cardioversion (p < 0.001). CONCLUSION: With appropriate training, a nurse led cardioversion service with sedation is safe, effective, well tolerated, and cost efficient.

Aged↗
PubMed2004

Evaluation and comparison of coronary heart disease risk factor profiles of children in a country with developing economy.

OBJECTIVE: To define the risk factors (RF) profile and prevalence rates of high risk factors in an urban Pakistani community and compare it to the RF profile and prevalence rates of Pakistan National Health Survey. METHODS: The present study included RF relevant data of 400 house hold children selected by open invitation as a part of Metroville Health Study (MHS), a risk factor modification study which was a cooperation between National Heart Lung Blood institute (NHLBI) USA and National Institute of Cardiovascular Diseases Pakistan. The base line data of 389 girls and 417 boys age 5-17 was included. PMRC data of 5067 and NHANES III survey data of 10,252 US children was used for comparison with MHS. RF analyzed were height weight, SBP, DBP, BMI and serum cholesterol. Comparisons between MHS and PMRC and US were made by using two tailed student t test and of high RF were defined as those exceeding US standards and expressed as percentages. RESULTS: The RF factor profile of urban Metroville children was worse than the national average of PMRC children. Except for diastolic blood pressure in both boys and girls and SBP in PMRC boys, all other RF were less than US children. Prevalence rates were higher in urban Metroville community, i.e., MHS compared to the PMRC which represents national average data. CONCLUSION: RF profile of Pakistani children has been presented and effect of urbanization demonstrated by comparing the PMRC and MHS RF profile. Hypertension in Pakistani children has emerged as a single most important RF requiring urgent prevention.

Adolescent↗
PubMed2004

A "healthy apatite" for bone repair.

Bone is unique in its ability to adapt structure to functional requirements, but as is all too obvious in an ever-ageing population it is susceptible to a number of degenerative diseases. Therefore there is an increasing need for materials for bone replacement. Clearly, the ideal material with which to replace bone, would be bone itself, but the major problem now facing us is that there is an insufficient supply of the natural bone to satisfy the clinical requirements. Hence, there is a need for the development of chemically synthesised bone graft substitutes

Animals↗
PubMed2003

Use of topically applied rt-PA in the evacuation of extensive acute spinal subdural haematoma.

Spontaneous spinal subdural haematoma is a rare cause of spinal cord compression, usually confined to a few vertebral levels. When the haematoma extends over several spinal segments, surgical decompression is a major undertaking. Recombinant tissue plasminogen activator (rt-PA) has previously been used in a number of surgical procedures, but not in the setting of acute spinal subdural haematoma. A minimally invasive technique of decompression, using topical rt-PA, is presented in two patients with extensive spinal intradural haematoma. Two patients receiving long-term anticoagulation therapy presented with acute-onset back pain progressing to paraparesis. Magnetic resonance imaging of the spine demonstrated spinal subdural haematomas extending over 15 vertebral levels in one patient and 12 in the other. An angiography catheter was introduced into the subdural space through a limited laminectomy. Thrombolysis and evacuation of haematoma was then achieved by intermittent irrigation of the subdural space with rt-PA, followed by saline lavage. Postoperative imaging demonstrated satisfactory decompression in both patients. There was significant improvement of neurological function in one patient. Topical application of rt-PA for spinal subdural haematoma allows evacuation of the haematoma through a limited surgical exposure. Decompression of the subdural space by this minimally invasive technique may be advantageous over extensive surgery by minimising surgical exposure, reducing postoperative pain and risk of neuronal injury. This technique may be useful in patients presenting with compression extending over several vertebral levels or poor surgical candidates.

Acute Disease↗
PubMed2003

Molecular cloning and characterisation of a novel GABAB-related G-protein coupled receptor.

Using a homology-based bioinformatics approach we have analysed human genomic sequence and identified the human and rodent orthologues of a novel putative seven transmembrane G protein coupled receptor, termed GABA(BL). The amino acid sequence homology of these cDNAs compared to GABA(B1) and GABA(B2) led us to postulate that GABA(BL) was a putative novel GABA(B) receptor subunit. The C-terminal sequence of GABA(BL) contained a putative coiled-coil domain, di-leucine and several RXR(R) ER retention motifs, all of which have been shown to be critical in GABA(B) receptor subunit function. In addition, the distribution of GABA(BL) in the central nervous system was reminiscent of that of the other known GABA(B) subunits. However, we were unable to detect receptor function in response to any GABA(B) ligands when GABA(BL) was expressed in isolation or in the presence of either GABA(B1) or GABA(B2). Therefore, if GABA(BL) is indeed a GABA(B) receptor subunit, its partner is a potentially novel receptor subunit or chaperone protein which has yet to be identified.

Amino Acid Sequence↗
PubMed2003

Expression of angiogenic factors during distraction osteogenesis.

Distraction osteogenesis is a unique and effective way to treat limb length inequality resulting from congenital and posttraumatic skeletal defects. However, despite its widespread clinical use, the cellular and molecular mechanisms by which this surgical treatment promotes new bone formation are not well understood. Previous studies in distraction osteogenesis have noted increased blood flow and vessel formation within the zone of distraction. These observations suggest that distraction osteogenesis may be driven in part by an angiogenic process. Using immunohistological analysis, the expression of two different angiogenic factors (VEGF and bFGF) was shown to localize at the leading edge of the distraction gap, where nascent osteogenesis was occurring. These cells were spatially adjacent to new vessels that were identified by staining for factor VIII. Microarray analysis detected maximal mRNA expression for a wide variety of angiogenic factors including angiopoietin 1 and 2, both Tie receptors, VEGF-A and -D, VEGFR2, and neuropilin 1. Expression of these factors was found to be maximal during the phase of active distraction. Expression of mRNA for extracellular matrix proteins and BMPs was also maximal during this period. A comparison between the patterns of gene expression in fracture healing and distraction osteogenesis revealed similarities; however, the expression of a number of genes showed selective expression in these two types of bone healing. These data suggest that bone formation during distraction osteogenesis is accompanied by the robust induction of factors associated with angiogenesis and support further investigations to elucidate the mechanisms by which angiogenic events promote bone repair and regeneration.

Angiogenesis Inducing Agents↗
PubMed2003

Comparison of in vivo dissolution processes in hydroxyapatite and silicon-substituted hydroxyapatite bioceramics.

The incorporation of silicate into hydroxyapatite (HA) has been shown to significantly increase the rate of bone apposition to HA bioceramic implants. However, uncertainty remains about the mechanism by which silicate increases the in vivo bioactivity of HA. In this study, high-resolution transmission electron microscopy was used to observe dissolution from HA, 0.8 wt% Si-HA and 1.5 wt% Si-HA implants after 6 and 12 weeks in vivo. Our observations confirmed that defects, in particular those involving grain boundaries, were the starting point of dissolution in vivo. Dissolution was observed to follow the order 1.5 wt% Si-HA>0.8 wt% Si-HA>pure HA and it was found to be particularly prevalent at grain boundaries and triple-junctions. These observations may help to explain the mechanism by which silicate ions increase the in vivo bioactivity of pure HA, and highlight the enhanced potential of these ceramics for biomedical applications.

Animals↗
PubMed2003

Age, diet and injury affect the survival of facial motoneurons.

Using the model of facial nerve avulsion, we have compared the effects of injury, age and diet on motoneuronal survival. One to four weeks after nerve avulsion, 50-75% motoneuron loss was quantified in ad libitum-fed rats aged 7 days (neonate), 6 months (adult) and 24 months (aging) at the time of injury. Evidence of apoptosis was found for neonatal rats at 3 days post-injury, but not for neonates examined 7 days or adult or aging rats examined 1 month after injury. Non-operated, ad libitum-fed rats showed no significant loss of facial motoneurons by 24 months. Surprisingly, non-operated rats whose food intake was restricted to 15 g standard rat chow per day from the age of 6 months lost 50% of their motoneurons by 24 months. Facial nerve avulsion of 24-month-old rats raised on this restricted diet did not result in any additional loss of motoneurons one month after injury. These results challenge the common view that aging results in neuronal loss and that dietary restriction is universally beneficial.

Aging↗
PubMed2003

Diazepam or midazolam for external DC cardioversion (the DORM Study).

AIMS: To compare the clinical efficacy and tolerability of two intravenous sedatives for physician-led DC cardioversion of atrial arrhythmias. METHODS AND RESULTS: One hundred and forty-one patients attending for elective DC cardioversion of atrial arrhythmias were randomized to intravenous midazolam or diazepam. Sedation was administered using titration protocols. Procedure times, operator satisfaction scores and adverse events were documented. The patients immediate, 24- and 48-h recall and awareness of after-effects were obtained from questionnaires. Seventy-one patients received midazolam (mean 12.5 mg) and 70 patients received diazepam (mean 28.1 mg). There were 16 minor adverse events with midazolam (20% hypotension, 3% oxygen desaturation) and nine with diazepam (7% hypotension, 6% required additional analgesia), P = 0.14. There were no major adverse events. Sedation time was 5.0 +/- 3.4 min for midazolam and 6.5 +/- 3.4 min for diazepam (P = 0.0016). Patients awoke 77 +/- 46 min post-sedation with midazolam and 39 +/- 24 min with diazepam (P < 0.0001). There was no recall of the procedure at 48 h and no difference in awareness of after-effects between the two groups at 24 or 48 h, P = ns. CONCLUSION: Physician-led cardioversion of atrial arrhythmias using intravenous sedation is effective and well tolerated. Sedation with diazepam was associated with fewer minor adverse events and a quicker recovery time than midazolam.

Atrial Fibrillation↗
PubMed2003

ENT presentations in children with HIV infection.

Illnesses of the ear, nose and throat (ENT) are common in children with human immunodeficiency virus (HIV) infection. We reviewed the case files of 107 HIV seropositive children in the paediatric HIV unit at St Mary's Hospital. The prevalence, age of onset and type of ENT disease were reviewed. We also determined sex distribution, maternal country of origin and mode of transmission of HIV. Fifty per cent of the HIV children had ENT illnesses. Fifty-five per cent of the children presented with their first ENT symptom before age 3 years with 98% of the children having ENT manifestations by age 9 years. The commonest ENT diseases were cervical lymphadenopathy (70%), otitis media (46%), oral candidiasis (35%) and adenotonsillar disease (31%). HIV transmission was vertical in 90%. Maternal country of origin was Africa in 70% and the UK in 13%. Compared with previous studies, the proportion of HIV children with ENT problems appears to have decreased. Although our figures report a similar ENT symptom profile, the age at onset of these symptoms has increased.

AIDS-Related Opportunistic Infections↗
PubMed2003

Liver microbubble transit time compared with histology and Child-Pugh score in diffuse liver disease: a cross sectional study.

BACKGROUND: A previous pilot study showed that early arrival time of a microbubble in a hepatic vein is a sensitive indicator of cirrhosis. AIM: To see if this index can also grade diffuse liver disease. PATIENTS: Thirty nine fasted patients with histologically characterised disease were studied prospectively. Nine patients had no evidence of liver fibrosis, 10 had fibrosis without cirrhosis, and 20 had cirrhosis (five Child's A, seven Child's B, and eight Child's C). METHODS: Bolus injections of a microbubble (Levovist; Schering, Berlin) were given intravenously, followed by a saline flush. Time intensity curves of hepatic vein and carotid artery spectral Doppler signals were analysed. Hepatic vein transit time (HVTT) was calculated as the time after injection at which a sustained signal increase >10% of baseline was seen. Carotid delay time (CDT) was calculated as the difference between carotid and hepatic vein enhancement. RESULTS: Diagnostic studies were achieved in 38/39 subjects. Both HVTT and CDT became consistently shorter with worsening disease, as follows (means (SD)): HVTT: no fibrosis 44 (25) s, fibrosis 26 (8) s, Child's A 21 (1) s, Child's B 16 (3) s, and Child's C 16 (2) s; CDT: no fibrosis 31 (29) s, fibrosis 14 (6) s, Child's A 8 (1) s, Child's B 4 (4) s, and Child's C 3 (3) s. These differences were highly significant (p<0.001, ANOVA comparison). A HVTT <24 s and a CDT <10 s were 100% sensitive for cirrhosis (20/20 and 18/18, respectively) but not completely specific: 2/8 subjects with fibrosis had CDT values <10 s and 3/9 had HVTT <24 s. CONCLUSION: This minimally invasive test shows promise not only in diagnosing cirrhosis but also in assessing disease severity.

Adult↗