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Biomedical subjects

A D Patel

Publications and source records attributed to A D Patel.

At least 19 recordsLinked to original sources
PubMed2006

Relationship of body mass index to early complications in hip replacement surgery : study performed at Hinchingbrooke Hospital, Orthopaedic Directorate, Huntingdon, Cambridgeshire.

The purpose of this study was to evaluate the relationship between body mass index and early complications following total hip replacements. Five hundred and fifty patients who underwent primary total hip replacement were recruited. All these patients were subjected to a pre-operative assessment and follow-up at 6 weeks and 1 year following surgery. Any complications occurring during this period were recorded. Complications were grouped into systemic and local, both subdivided into minor and major depending on the risk involved. Fifty-six patients (10.2%) had an early complication following hip replacement surgery. Forty-four patients (8%) had a major local complication. Overall, there did seem to be a weak correlation between BMI and the rate of complications, with a p value of 0.104. A correlation was also found between the surgeon and presence of complications with a p value of 0.736. There is a weak correlation between BMI and early complications following hip replacement surgery, and there also seems to be a correlation between the operating surgeon and early complications, but this is not statistically significant.

Adult↗
PubMed2006

Bone morphogenetic proteins in orthopaedic trauma: recent clinical findings with human bone morphogenetic protein-2 (rhBMP-2).

This article introduces papers based on presentations from a symposium entitled "Bone Morphogenic Protein Advisory Meeting in Orthopaedic Trauma", where recent clinical findings with human bone morphogenetic protein-2 (rhBMP-2) were reviewed. It also presents two case studies which illustrate the clinical problems with the potential morbidity of tibial fractures and the potential benefits of the use of rhBMP-2 at surgery. The article concludes with a summary of the symposium. Tibial shaft fracture repair is associated with a significant financial burden on the patient, the health care providers and the medical insurance companies. It is anticipated that the clinical advantages of rhBMP-2 could lead to cost savings both inside and outside the hospital setting.

Adult↗
PubMed2006

Prosodic discrimination in patients with schizophrenia.

Fifteen patients with prominent positive symptoms of schizophrenia and 15 normal controls performed verbal prosodic and pure musical discrimination tasks, with changes in pitch and timing parameters. The patients' performance was comparable to that of controls on the discrimination of terminal pitch changes, but significantly poorer on the more difficult internal pitch discrimination. The latter deficit was positively correlated with the severity of their positive symptoms. The results suggest that patients have a deficit in processing fundamental aspects of prosody, which is associated with the presence of positive symptoms.

Adult↗
PubMed2005

Ghrelin stimulates insulin-induced glucose uptake in adipocytes.

The gastric and hypothalamic hormone ghrelin is the endogenous agonist of the growth hormone secretagogue receptor GHS-R1(a). Ghrelin stimulates growth hormone release and appetite via the hypothalamus. However, putative direct peripheral effects of ghrelin remain poorly understood. Rat adipose tissue expresses GHS-R1(a) mRNA, suggesting ghrelin may directly influence adipocyte function. We have investigated the effects of ghrelin on insulin-stimulated glucose uptake in isolated white adipocytes in vitro. RT-PCR confirmed the expression of GHS-R1(a) mRNA in epididymal adipose tissue. However, GHS-R1(a) expression was not detected in the peri-renal fat pads. Ghrelin increased insulin-stimulated deoxyglucose uptake in isolated white adipocytes extracted from the epididymal fat pads of male Wistar rats. Ghrelin 1000 nM significantly increased deoxyglucose uptake by 55% in the presence of 0.1 nM insulin. However, ghrelin administration in the absence of insulin had no effect on adipocyte deoxyglucose uptake, suggesting that ghrelin acts synergistically with insulin. Des-acyl ghrelin, a major circulating non-octanylated form of ghrelin, had no effect on insulin-stimulated glucose uptake. Furthermore, acylated ghrelin had no effect on deoxyglucose uptake in adipocytes from peri-renal fat pads suggesting that ghrelin may influence glucose uptake via the GHS-R1(a). Ghrelin therefore appears to directly potentiate adipocyte insulin-stimulated glucose uptake in selective adipocyte populations. Ghrelin may play a role in adipocyte regulation of glucose homeostasis.

Adipocytes↗
PubMed2005

A new approach for plate fixation of midshaft clavicular fractures.

The majority of midshaft clavicle fractures unite uneventfully. Although the indications for operative intervention are limited and reported complication rates high, there are circumstances in which surgery is required. We describe a new, infraclavicular surgical approach to the clavicle used in a series of 89 patients over 9 years. Average time to union was 13.5 weeks. There was one case of deep infection and one of non-union, both of which resolved with further treatment. These results compare very favourably with previously published series and we submit that this operative approach allows safe management of an otherwise potentially hazardous procedure.

Adult↗
PubMed2001

Wilson disease.

Explore the source record for details and available documents.

Adult↗
PubMed2001

Low-level determination of polymorph composition in physical mixtures by near-infrared reflectance spectroscopy.

Near-infrared reflectance spectroscopy (NIRS) was employed to quantify sulfathiazole (STZ) forms I and III in binary physical mixtures in which one form was the dominant component. Physical mixtures of the polymorph pair were made by weight, ranging from 0 to 5% STZ form I mixed with STZ form III, and near-infrared spectra of the powder samples contained in glass vials were obtained over the wavelength region of 1100 to 2500 nm. A calibration plot was constructed by plotting STZ form I weight percent against a ratio of second-derivative values of log (1/R') (where R' is the relative reflectance) versus wavelength. The coefficients of determination, R(2), were > 0.9983 and standard errors were low for these calibration models. The instrument reproducibility, method error, and limits of detection (LOD) and quantification (LOQ) of the method were assessed. The LOD and LOQ were determined from the standard deviation of the response of the 0% analyte sample (0% STZ form I containing 100% STZ form III). The LOQ was subsequently validated with independently prepared samples. The results show that polymorphs can be quantified in binary physical mixtures in the 0.3% polymorph composition range. These studies indicate that NIRS is a precise and accurate quantitative tool for determination of polymorphs in the solid state, is comparable to other characterization techniques, and is more convenient to use than many other methods.

Calibration↗
PubMed2001

Human pitch perception is reflected in the timing of stimulus-related cortical activity.

'Pitch' refers to a sound's subjective highness or lowness, as distinct from 'frequency,' which refers to a sound's physical structure. In speech, music and other natural contexts, complex tones are often perceived with a single pitch. Using whole-head magnetoencephalography (MEG) and stimuli that dissociate pitch from frequency, we studied cortical dynamics in normal individuals who extracted different pitches from the same tone complexes. Whereas all subjects showed similar spatial distributions in the magnitude of their brain responses to the stimuli, subjects who heard different pitches exhibited contrasting temporal patterns of brain activity in their right but not their left hemispheres. These data demonstrate a specific relationship between pitch perception and the timing (phase) of dynamic patterns of cortical activity.

Acoustic Stimulation↗
PubMed2001

Calcaneal compartment syndrome after tibial fractures.

Compartment syndrome of the newly discovered calcaneal compartment of the foot is a theoretical possibility following tibial fracture due to the communication with the deep posterior compartment of the calf. Forty-nine patients were reviewed at least 18 months after open or closed tibial shaft fractures treated with tibial nailing in order to determine the prevalence of foot deformities secondary to previously undetected calcaneal or leg compartment syndromes. Ankle movements, foot height, length of feet and degree of clawing of the toes were all measured and compared with the unaffected opposite side. None of the patients complained of any symptoms from their feet and none had any significant foot deformities. Calcaneal compartment syndrome is rare after tibial fracture and routine measurement of calcaneal compartment pressures after such injuries is not indicated.

Bone Nails↗
PubMed2001

Thyroglobulin messenger ribonucleic acid levels in the peripheral blood of children with benign and malignant thyroid disease.

Reverse transcriptase-PCR has identified thyroglobulin mRNA (Tg mRNA) in peripheral blood of normal adults and adults with thyroid cancer. However, no children were studied. The primary objective of this study was to determine whether whole blood Tg mRNA levels differ between benign and malignant thyroid disease in children. The secondary goals were to determine whether whole blood Tg mRNA levels vary with age or pubertal development among children with thyroid disease. Whole blood Tg mRNA levels were determined in 38 children (29 girls, nine boys; median age, 14.5 y; range, 4.8-20.4 y) with benign and malignant thyroid disease and correlated with diagnosis, age, pubertal status, thyroid size, and serum levels of free thyroxine, TSH, and Tg protein. Tg mRNA levels ranged from 3.3 to 104 pg Eq/microg total thyroid RNA (mean, 28 +/- 20.2 pg Eq/microg total thyroid RNA) and were similar in benign and malignant disorders (p = 0.67). However, in children with previously treated papillary thyroid cancer, Tg mRNA levels directly correlated with total body (131)I uptake (p = 0.026) and serum Tg protein (p = 0.037). There was no difference between boys and girls, and no change with pubertal maturation. In children with benign thyroid disease, Tg mRNA levels correlated with serum TSH (p = 0.031), but not with diagnosis, age, Tanner stage, or thyroid size. We conclude that Tg mRNA levels are similar in children with benign and malignant thyroid disease and unchanged by age or pubertal status, but correlated with tumor burden in previously treated papillary thyroid cancer.

Adolescent↗
PubMed2000

Quantitative analysis of polymorphs in binary and multi-component powder mixtures by near-infrared reflectance spectroscopy.

Near-infrared reflectance spectroscopy was employed to quantify polymorphs in binary and multi-component powder mixtures. Sulfamethoxazole (SMZ) forms I and II were used as model polymorphs for this study. The instrument reproducibility, method error, precision, and limits of detection and quantification of the method were assessed. Physical mixtures of the polymorph pair were made by weight, ranging from 0 to 100% SMZ form I in II. Near-infrared spectra of the powder samples contained in glass vials were obtained over the wavelength region of 1100-2500 nm. A calibration plot was constructed by plotting SMZ form I weight percent against a ratio of second derivative values of log(1/R') (where R' is the relative reflectance) versus wavelength. The coefficients of determination, R(2), were generally greater than 0.9997 and standard errors were low for all the systems. Instrument error was assessed by analyzing a sample 10 times without perturbation. Method error was assessed in the same manner except the sample was re-mixed between analyses. A precision study was conducted by analyzing aliquots from a larger homogeneous sample. Limits of detection (LOD) and quantification (LOQ) were determined from the standard deviation of the response of the blank samples (100% SMZ form II, undiluted or diluted with 60% lactose). These limits were subsequently validated with independent samples. The results show that polymorphs can be quantified in binary and multi-component mixtures in the 2% polymorph composition range. These studies indicate that NIRS is a precise and accurate quantitative tool for determination of polymorphs in the solid-state, is comparable to other characterization techniques, and is more convenient to use than many other methods.

Anti-Infective Agents↗
PubMed2000

Temporal patterns of human cortical activity reflect tone sequence structure.

Despite growing interest in temporal aspects of auditory neural processing, little is known about large-scale timing patterns of brain activity during the perception of auditory sequences. This is partly because it has not been possible to distinguish stimulus-related activity from other, endogenous brain signals recorded by electrical or magnetic sensors. Here we use amplitude modulation of unfamiliar, approximately 1-minute-long tone sequences to label stimulus-related magnetoencephalographic neural activity in human subjects. We show that temporal patterns of activity recorded over particular brain regions track the pitch contour of tone sequences, with the accuracy of tracking increasing as tone sequences become more predictable in structure. In contrast, temporal synchronization between recording locations, particularly between sites over the left posterior hemisphere and the rest of the brain, is greatest when sequences have melody-like statistical properties, which may reflect the perceptual integration of local and global pitch patterns in melody-like sequences. This method is particularly well suited to studying temporal neural correlates of complex auditory sequences (such as speech or music) which engage multiple brain areas as perception unfolds in time.

Auditory Perception↗
PubMed1999

Routine radiography following ankle fracture fixation: a case for limiting its use.

The use of fluoroscopic screening in the orthopaedic theatre is a necessary operative aid in many procedures. Modern systems give good image resolution and allow the production of per-operative hard-copy prints. This study was performed to compare these prints with postoperative radiographs in 41 patients who underwent internal fixation for an ankle fracture in a 6-month period. The hard-copy prints and the postoperative X-ray films were independently assessed for several features, which included status of the tibiofibular syndesmosis, fibular length, talo-crural angle, talar tilt, presence and size of a posterior malleolar fracture, and abnormality of the medial clear space. Information was also recorded as to whether there had been a change in postoperative management plan after review of the check X-ray. Of the 41 cases, 30 were suitable for full assessment. In 25 of these cases there was no difference in the information provided by the hard-copy prints from fluoroscopic images and the postoperative check X-rays. In the other five cases, the differences were not significant. In none of the cases did the check X-ray effect a change in postoperative management. We therefore suggest that if per-operative hard-copy prints are obtained from the fluoroscopic images, postoperative radiographs of the ankle are only necessary in exceptional circumstances.

Adult↗
PubMed1999

Quantitative reverse transcription-PCR measurement of thyroglobulin mRNA in peripheral blood of healthy subjects.

BACKGROUND: Thyroglobulin mRNA can be detected qualitatively in the peripheral blood of patients with metastatic thyroid cancer, thyroid cancer patients with residual thyroid bed uptake, and individuals with no known thyroid disease with intact thyroid glands by use of a lengthy, highly sensitive extraction technique. To improve and broaden the clinical usefulness of this assay, we developed a quantitative reverse transcription (RT)-PCR assay for thyroglobulin mRNA, using RNA recovered from whole blood with a simplified extraction technique. METHODS: Whole blood was drawn from 32 healthy subjects in standard EDTA blood collection tubes. Total RNA was extracted from whole blood, using the PUREscript RNA Isolation Kit. RT-PCR using intron-spanning primers was used to quantitatively amplify thyroglobulin mRNA, using the ABI PRISM 7700 Sequence Detection System with a fluorescent-labeled, thyroglobulin-specific oligonucleotide probe. Thyroid RNA calibration curves were created using total RNA recovered from a single nondiseased thyroid gland. RESULTS: Qualitative RT-PCR demonstrated the presence of thyroglobulin mRNA in the whole blood sample of each healthy subject. The mean concentration of thyroglobulin mRNA detected in these subjects was 433 +/- 69 ng of total thyroid RNA per liter of whole blood (range, 26-1502 ng/L). Overall assay imprecision (CV) was 24% for five samples analyzed 10 times each in separate analytical runs on different days. CONCLUSIONS: Thyroglobulin mRNA can be accurately detected and quantified in peripheral blood from healthy subjects. This new quantitative technique may improve the clinical utility of circulating thyroglobulin mRNA detection in patients with thyroid disease.

Humans↗