Search PubMed⌕ Search

Biomedical subjects

J Shah

Publications and source records attributed to J Shah.

At least 19 recordsLinked to original sources
PubMed2006

SARS transmission in Vietnam outside of the health-care setting.

To evaluate the risk of transmission of SARS coronavirus outside of the health-care setting, close household and community contacts of laboratory-confirmed SARS cases were identified and followed up for clinical and laboratory evidence of SARS infection. Individual- and household-level risk factors for transmission were investigated. Nine persons with serological evidence of SARS infection were identified amongst 212 close contacts of 45 laboratory-confirmed SARS cases (secondary attack rate 4.2%, 95% CI 1.5-7). In this cohort, the average number of secondary infections caused by a single infectious case was 0.2. Two community contacts with laboratory evidence of SARS coronavirus infection had mild or sub-clinical infection, representing 3% (2/65) of Vietnamese SARS cases. There was no evidence of transmission of infection before symptom onset. Physically caring for a symptomatic laboratory-confirmed SARS case was the only independent risk factor for SARS transmission (OR 5.78, 95% CI 1.23-24.24).

Adolescent↗
PubMed2006

Botulinum toxin and the overactive bladder.

Botulinum toxin is now a treatment for many conditions. It is undergoing increasing use in several different unlicensed urological clinical situations which are outlined in this article. The article discusses the available evidence relating to its use, effectiveness and safety.

Botulinum Toxins, Type A↗
PubMed2005

Historical trends in reported survival rates in patients with hypertrophic cardiomyopathy.

OBJECTIVE: To determine the range of survival rates of patients with hypertrophic cardiomyopathy (HCM) by comparing and contrasting the natural history of a cohort of patients seen between 1988 and 2002 with that of other published series. METHODS: 956 adult (> or = 16 years old) patients with HCM (572 men, mean (SD) age 42 (15) years, range 16-88) were evaluated by ECG, Holter, exercise testing, and echocardiography. Patient characteristics and survival data were compared with those in natural history studies from referral and non-referral centres published between 1960 and January 2003. RESULTS: The duration of follow up was 69 (45) months. 120 (12.6%) patients died or underwent cardiac transplantation. Sudden cardiac death (n = 48) was the most common mode of death. The annual rate of sudden death or implantable cardioverter-defibrillator discharge was 1.02 (95% confidence interval (CI) 0.76 to 1.26). Annual rates for heart failure death or transplantation and stroke related death were 0.55% (95% CI 0.37% to 0.78%) and 0.07% (95% CI 0.02% to 0.19%), respectively. When studies published within the last 10 years of the study period were compared with earlier reports, the size of individual study cohorts was larger (309 (240.6) v 136.5 (98.8), p = 0.058) and the proportion with severe functional limitation NYHA class III/IV lower (12.4% v 24.8%, p < 0.0001), and fewer patients underwent septal myotomy-myectomy (5.2% v 18.7%, p < 0.0001). Published sudden death rates over the last 10 years were lower than previously published figures (median 1.0% (range 0.1-1.7) v 2.0% (0-3.5)). CONCLUSION: Published survival rates in HCM cohorts have improved progressively over the past 40 years. In the modern era the prevalence of disease related complications is similar in all reporting centres.

Adolescent↗
PubMed2005

Instrument to measure the heat convection coefficient on the endothelial surface of arteries and veins.

The primary objective of the paper was to present the design and analysis of an instrument to measure the heat convection coefficient h on the endothelial surfaces of arteries and veins. An invasive thermistor probe was designed to be inserted through the vessel wall and positioned on the endothelial surface. Electrical power was supplied to the thermistor by a constant temperature anemometry circuit. Empirical calibrations were used to relate electrical measurements in the thermistor to the h at the endothelial surface. As the thermal processes are strongly dependent on baseline blood temperature, the instrument was calibrated at multiple temperatures to minimise this potentially significant source of error. Three different sizes of thermistor were evaluated to optimise accuracy and invasiveness, and the smallest thermistors provided the best results. The sensitivity to thermistor position was evaluated by testing the device at multiple locations, varying both depth of thermistor penetration and position along the vessel. Finally, the measurement accuracy of the instrument was determined for the range of h from 430 to 4200 W m(-2)K, and the average error of the reading was 4.9% for the smallest thermistor. Although the instrument was designed specifically for measurements in the portal vein to obtain useful data for current numerical modelling, the device can be used in any large vessel.

Catheter Ablation↗
PubMed2005

Height does not predict ureteric length.

AIM: To establish whether ureteric length correlates with an individual's height. METHOD: A prospective study was performed involving 25 patients. The height of each participant was determined, and also actual ureteric length by direct measurement using a ureteric catheter. Simple regression analyses were carried out, using a p value of 0.05 as the level of significance. RESULTS: Height did not correlate with the actual ureteric length (p=0.54). CONCLUSION: Height does not predict obstructed ureteric length.

Adult↗
PubMed2005

Genetic background regulates semaphorin gene expression and epileptogenesis in mouse brain after kainic acid status epilepticus.

The host response to neural injury, which can include axonal sprouting and synaptic reorganization is likely to be under tight genetic regulatory control at the level of the genome and may be implicated in epileptogenesis. Despite its importance, however, the molecular basis of synaptic reorganization is unclear. We have studied the development of synaptic reorganization, semaphorin gene expression, and epileptogenesis in hippocampus of epileptogenic sensitive (FVB/NJ) and epileptogenic resistant (C57BL/6J) mice (i.e. distinct genetic backgrounds) after kainic acid-induced status epilepticus. Our results support the hypothesis that disruption of transcriptional regulation of axon guidance genes leads to a differential loss of tonic neuropilin-2 dependent activation of semaphorin 3F receptors on hippocampal neurons on distinct genetic backgrounds. This results in rearranged synaptic circuitry and thus promotes epileptogenesis. These findings may define biologic principles underlying the role of semaphorin signaling which may broadly apply to other systems undergoing neural regeneration.

Animals↗
PubMed2005

Prostate abscess presenting as priapism.

Abscesses of the prostate are infrequently encountered now as a result of effective antibiotics. The clinical diagnosis remains difficult. Herein we report an unusual case of a prostate abscess presenting as priapism. The diagnosis and management of the case is discussed, and the literature is reviewed.

Abscess↗
PubMed2005

Three-dimensional metallo-dielectric photonic crystals with cubic symmetry as stacks of two-dimensional screens.

Metallo-dielectric photonic crystals with cubic symmetries have been studied here both experimentally and theoretically in the millimeter wavelength region (15-60 mm). In a direct analogy to linear systems, we considered the three-dimensional lattices as a stack of two-dimensional resonating screens. The overall three-dimensional structure was introduced in the calculation through a structural phase. Such an approach proved useful in understanding the related mode propagation and guided us in a study of the transition between cubic and centered body cubic symmetries.

Journal Article↗
PubMed2004

Novel SCO2 mutation (G1521A) presenting as a spinal muscular atrophy type I phenotype.

Rare cases of suspected spinal muscular atrophy (SMA) have been found to have cytochrome c oxidase (COX) deficiency. To date, four cases with SMA features have been reported in children with mutations in the synthesis of cytochrome oxidase 2 (SCO2) gene. We report a male neonate who was born hypotonic, with persistent lactic acidosis, spontaneous activity with EMG testing, development of respiratory distress in the first few hours of life, and died at 30 days of age with progressive cardiomyopathy. Testing for survival motor neurone (smn) and NAIP deletions were negative and a skeletal muscle biopsy showed neurogenic features with severe reductions of COX enzymatic and histochemical staining intensity. Post-mortem muscle, heart, and liver biopsies showed severe, moderate, and mild reductions in COX activity, respectively, with parallel findings in the protein content for the mitochondrial DNA (COII) and nuclear DNA (COIV) encoded subunits. DNA sequencing of exon 2 of the SCO2 gene revealed compound heterozygosity with mutations at G1541A (common mutation, E140K) and also at a novel site in the copper binding region (G1521A in the current case (converting a highly conserved cysteine to tyrosine [corrected] (C133Y) [corrected]); mother heterozygous for G1521A; and father heterozygous for G1541A). This case provides strong support that SCO2 mutations can result in neonatal hypotonia with an SMA 1 phenotype. SCO2 mutations should be screened in suspected SMA cases with normal smn mutation analysis and any one of; cardiomyopathy, lactic acidosis, or COX deficiency in muscle.

Biopsy↗
PubMed2004

Is continuous spinal analgesia via an epidural catheter appropriate after accidental subarachnoid administration of 15 mL of bupivacaine 0.1% containing fentanyl 2 micrograms/mL?

We report a case of accidental insertion of an epidural catheter into the subarachnoid space and accidental administration of 15 mL of bupivacaine 0.1% with fentanyl 2 micrograms/mL, in the sitting position, during labour. Within 5 min, the patient was unable to move her lower limbs. Although the upper level of the sensory block using ethyl chloride was found to be T5, there was no cardiovascular depression. The catheter was left in situ and used for continuous spinal analgesia. Further administration of the bupivacaine-fentanyl solution was not required until after 315 min. The patient was given five further 2- to 3-mL top-up doses of bupivacaine-fentanyl at intervals of 105 to 145 min. After 16 h, caesarean section was performed for failure to progress in the first stage of labour. This was conducted under spinal anaesthesia using 2 mL of hyperbaric bupivacaine 0.5% with fentanyl 20 micrograms. A healthy baby was delivered with Apgar scores of 10 and 10, at 1 and 5 min, respectively. There was no postdural puncture headache or any neurological complications.

Adult↗
PubMed2004

Is routine post-operative haemoglobin measurement required after transurethral resection of the prostate?

The aim of this study is to evaluate the rate of blood transfusion during the post-operative period in patients undergoing transurethral resection of the prostate (TURP) and to determine the value of using post-operative haemoglobin (Hb) measurement as a guide to transfusion requirements. In a retrospective study, pre- and post-operative Hb measurements and the resected prostatic tissue weights were recorded for 106 patients. There was a statistically significant change in the Hb concentration within 48 h of the operation (P < 0.0001), although this was clinically insignificant in the majority of patients. The post-operative blood transfusion rate was 0.85% and there was a significant correlation between change in Hb concentration and the resected tissue weight (P < 0.0001). Our results show that routine post-operative Hb is not necessary in patients following a TURP.

Aged↗
PubMed2004

Acute idiopathic scrotal oedema in an adult: a case report.

In the evaluation of a patient of any age presenting with an acute scrotal swelling, a surgical emergency should be carefully excluded. However, acute idiopathic scrotal oedema must be considered to avoid unnecessary surgical exploration.

Adult↗
PubMed2004

MRI of spinal intradural arachnoid cyst formation following tuberculous meningitis.

Secondary intradural arachnoid cyst involving the spine is uncommon. It is usually secondary to trauma, haemorrhage, surgery or inflammation. We present two cases of treated tuberculous meningitis, which presented with gradual onset of quadriplegia and paraplegia, respectively. MRI revealed intradural (cervical and thoracic) arachnoid cysts (ventral and dorsal to the spinal cord) with myelomalacic cord changes. Ventral location of such spinal arachnoid cysts, and being secondary to tuberculous arachnoiditis are distinctively uncommon features. The rarity of this condition and the relevance of MRI in the accurate diagnosis have been discussed here.

Adult↗
PubMed2003

Depth cue reliance in surgeons and medical students.

BACKGROUND: Depth perception is reduced in endoscopic surgery, although little is known about the effect this has on surgical performance. METHODS: To assess the role of depth cues, 45 subjects completed tests of depth cue reliance. Surgical skill was assessed using the Minimally Invasive Surgical Trainer-Virtual Reality, a previously validated laparoscopic simulator. RESULTS: We could demonstrate no difference in cue reliance for three depth cues--namely stereo, texture, and outline--between surgeons and medical students. Greater dominance on stereo for medical students was a positive finding and a negative finding for the surgeons when correlated with surgical performance. CONCLUSIONS: We suggest that surgeons learn to adapt to the nonstereo environment in MIS, and this is the first study to show evidence of this phenomenon. This difference in stereo reliance is a reflection of the experience that surgeons have with laparoscopy compared with medical students, who have none.

Adult↗
PubMed2003

Can tonic accommodation predict surgical performance?

BACKGROUND: Pilots undergo many visual tests for both selection and assessment, and we know that there are many similarities between pilots and surgeons. Hence, it would not be unreasonable to bring similar visual tests into surgery. Tonic accommodation (TA) is a stable parameter that is adopted by the eye in the absence of any stimulation. Over recent years, surgery has undergone change from traditional open surgery to minimally invasive procedures, bringing many advantages. However, not every surgeon has the ability to perform under conditions where the operative field is represented on a flat monitor. METHOD: We determined the TA values in medical students and then correlated this with their performance on a virtual reality surgical simulator. RESULTS: We found that TA values predicted the number of errors made with the dominant hand, accounting for 27% of the variance. CONCLUSION: The data suggest that TA may play a role in the individual differences that are noted when surgeons perform laparoscopic surgery. Further studies are needed to evaluate the exact role of TA in surgical performance.

Accommodation, Ocular↗