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Biomedical subjects

G Joseph

Publications and source records attributed to G Joseph.

At least 19 recordsLinked to original sources

Predictive indicators for thyroid cartilage involvement in carcinoma of the larynx seen on spiral computed tomography scans.

OBJECTIVES: Recent studies have shown that the spiral computed tomography (CT) scan is a sensitive imaging modality for predicting neoplastic invasion of thyroid cartilage. The objectives of our study were: to assess the accuracy of pre-operative spiral CT in predicting thyroid cartilage involvement in patients with carcinoma of the larynx; and to elucidate the factors that would accurately indicate cartilage involvement. MATERIAL AND METHODS: Medical records, including spiral CT scans and pathological reports, were reviewed for 27 patients who had undergone laryngectomy in two major hospitals in south Wales. A consultant radiologist with special interest in cross-sectional imaging re-evaluated the scans to assess neoplastic involvement of the thyroid cartilage, based on definite, objective criteria. These criteria included: soft tissue asymmetry; loss of medullary space; spiky or irregular surface; distortion of cartilage framework; and abnormal soft tissue on both sides of the cartilage. The radiological findings were then correlated with the histopathological evidence of cartilage invasion by the tumour. RESULTS: Out of the 27 cases, 15 had evidence of histological invasion of thyroid cartilage. The most specific criterion to predict thyroid cartilage involvement was the presence of tumour on both sides of the cartilage (specificity of 91 per cent, sensitivity of 66 per cent). Combining two criteria increased both the sensitivity and the specificity to 86 and 91 per cent, respectively.

Carcinoma↗

Delayed hydrocephalus as an unusual complication of a stab injury to the spine.

STUDY DESIGN: Case report. OBJECTIVE: To report a rare complication following a stab injury to the upper cervical spine and cord. SETTING: National spinal injury unit in a Scottish university teaching hospital. CASE REPORT: A 19-year-old male sustained a stab injury to his upper cervical spine, with a partial cord transection. After 5 months of rehabilitation, his condition deteriorated. CT scans showed hydrocephalus, which was treated by shunting. After shunting, the patient's condition improved but he remained tetraplegic requiring ventilatory support at night. CONCLUSION: Hydrocephalus as a late complication of a cervical spine injury is rare but should be considered if the condition of the patient with an upper cervical spine injury deteriorates. The likely mechanism of the hydrocephalus development is also discussed.

Adult↗

Spinal cord infarction due to a self-inflicted needle stick injury.

STUDY DESIGN: Case report. OBJECTIVE: To report a case of spinal cord infarction after a self-inflicted needle stick injury, following an injection of heroin into the cord. SETTING: National spinal injury unit in a Scottish University teaching hospital, Glasgow, UK. CASE REPORT: A 20-year-old male, injected street heroin accidentally into the cord through the left side of the neck, leading to sudden loss of power to all four limbs. Initial magnetic resonance imaging scans showed extensive cord oedema and follow-up scans showed signal changes within the anterior horns of the spinal cord in keeping with a cord infarct. CONCLUSION: Self-inflicted spinal cord injury with a small needle is difficult, but not impossible. Cord infarct as a result of a self-inflicted injury has not been previously reported. The mechanism of the injury resulting in cord infarction is explained by the vascular anatomy of the spinal cord circulation, and this may also explain the residual neurological status of the patient.

Adult↗

ECG analysis for sleep apnea detection.

OBJECTIVES: The objective of our study was to find out whether obstructive sleep apnea (OSA) may be detected on ECGs recorded during sleep. METHODS: We have analyzed 70 eight-hour single-channel ECG recordings taken at polysomnographia. The 70 data sets were annotated for definition of regular sleep and phases with sleep apnea. From the 70 data sets, 35 have been used as a learning set. Our analysis is based on spectral components of heart rate variability. Frequency analysis was performed using Fourier and wavelet transformation with appropriate application of the Hilbert transform. Classification is based on four frequency bands: ULF band (0-0.013 Hz), VLF band (0.013-0.0375 Hz), LF band (0.0375-0.06 Hz) and the HF band (0.17-0.28 Hz). Linear discriminant functions were applied using mainly spectral components derived from the records. Classification of cases was based on three variables. RESULTS: For the Testing Set, a sensitivity (Se) for apnea of 92.3% at a specificity (Sp) of 94.6% was achieved. For the minutes allocation on the Learning Set Se was 90.8% at Sp 92.7%. CONCLUSION: ECG analysis is useful for the detection of sleep apnea and may help to differentiate causes of cardiac arrhythmias.

Electrocardiography↗

Patient-controlled epidural analgesia versus continuous infusion for labour analgesia: a meta-analysis.

BACKGROUND: Patient-controlled epidural analgesia (PCEA) is a relatively new method of maintaining labour analgesia. There have been many studies performed that have compared the efficacy of PCEA with continuous epidural infusion (CEI). The purpose of this systematic review is to compare the efficacy and safety of PCEA and CEI. METHODS: All randomized controlled trials that compared PCEA, without background infusion, with CEI were sought from the literature. These were rated for quality using a validated, five-point scale. The primary outcome was the number of patients who received anaesthetic interventions. Secondary outcomes included the dose of local anaesthetic, incidence of motor block, quality of analgesia, obstetric and safety outcomes. Where feasible, the data were combined using meta-analytical techniques. For dichotomous data, the risk difference (RD) and 95% confidence intervals (CI) were calculated. For continuous data, the weighted mean differences (WMD) were calculated. The differences were statistically significant when the 95% CI excluded 0. RESULTS: Nine studies comprised of 640 patients were found. There were fewer anaesthetic interventions in the PCEA group (RD, 27%; 95% CI, 18-36%; P < 0.00001). This group also received less local anaesthetic (WMD, -3.92; 95% CI, -5.38 to -2.42; P < 00001) and less motor block (RD, 18%; 95% CI, 6-31%; P = 0.003). Both methods were safe for mother and newborn. CONCLUSION: Patients who receive PCEA are less likely to require anaesthetic interventions, require lower doses of local anaesthetic and have less motor block than those who receive CEI. Future research should be directed at determining differences in maternal satisfaction and obstetric outcome.

Analgesia, Epidural↗

RNA-binding strategies common to cold-shock domain- and RNA recognition motif-containing proteins.

Numerous RNA-binding proteins have modular structures, comprising one or several copies of a selective RNA-binding domain generally coupled to an auxiliary domain that binds RNA non-specifically. We have built and compared homology-based models of the cold-shock domain (CSD) of the Xenopus protein, FRGY2, and of the third RNA recognition motif (RRM) of the ubiquitous nucleolar protein, nucleolin. Our model of the CSD(FRG)-RNA complex constitutes the first prediction of the three-dimensional structure of a CSD-RNA complex and is consistent with the hypothesis of a convergent evolution of CSD and RRM towards a related single-stranded RNA-binding surface. Circular dichroism spectroscopy studies have revealed that these RNA-binding domains are capable of orchestrating similar types of RNA conformational change. Our results further show that the respective auxiliary domains, despite their lack of sequence homology, are functionally equivalent and indispensable for modulating the properties of the specific RNA-binding domains. A comparative analysis of FRGY2 and nucleolin C-terminal domains has revealed common structural features representing the signature of a particular type of auxiliary domain, which has co-evolved with the CSD and the RRM.

Amino Acid Motifs↗

Percutaneous recanalization and balloon angioplasty of congenital isolated local atresia of the aortic isthmus in adults.

Congenital isolated local atresia of the aortic isthmus is anatomically similar and morphogenetically related to congenital coarctation of the aorta and was encountered in 4 out of 26 consecutive adult patients selected for coarctation angioplasty at our center. Anterograde recanalization of the atresia was safely and successfully accomplished in all four patients, using a brachial approach. Balloon dilation in the four patients, with ancillary stent implantation in one patient, resulted in reduction of translesion gradient from 84 +/- 11 mm Hg to 9 +/- 7 mm Hg without complications. Angiography in the three non-stented patients after a mean follow-up of 13 months showed no evidence of restenosis, dissection or aneurysm formation, though one patient had mild dilatation of the posterior aspect of the aortic isthmus. The clinical presentation of patients with isolated local aortic atresia, and their short- to mid-term response to percutaneous treatment, is similar to that of patients with isolated severe coarctation of aorta.

Adolescent↗

Response of some scolytids and their predators to ethanol and 4-allylanisole in pine forests of central Oregon.

Lindgren multiple funnel traps were set up in pine forests of central Oregon to determine the response of scolytid bark beetles to ethanol and 4-allylanisole (4AA). Traps were baited with two release rates of ethanol (4.5 or 41.4 mg/hr) and three release rates of 4AA (0, 0.6, or 4.3 mg/hr) in a 2 x 3 factorial design. All traps also released a 1:1 mixture of alpha- and beta-pinene at 11.4 mg/hr. Of 13,396 scolytids caught, Dendroctonus valens made up 60%, Hylurgops spp. 18.5%, Ips spp. 16%, Hylastes spp. 1.8%, Ganthotrichus retusus 0.9%, and bark beetle predators another 2.8%. Increasing the release rate of ethanol in the absence of 4AA increased the number of most scolytid species caught by 1.5-3.7 times, confirming its role as an attractant. Ips latidens, Temnochila chlorodia, and clerid predators were exceptions and did not show a response to higher ethanol release rates. Release of 4AA at the lowest rate inhibited attraction of most scolytids, with a significant reduction in G. retusus, Hylastes macer, and Hylurgops porosus when compared to traps without 4AA. A high release rate of 4AA further inhibited responses for most beetles compared to low 4AA. Seven species were significantly deterred by high 4AA, including the latter three, and Hylastes longicollis, Hylastes nigrinus, Hylurgops reticulatus, and Ips latidens. Exceptions include Hylurgops subcostulatus, which was significantly attracted to both low and high 4AA, and I. pini, which was attracted to low and high 4AA in combination with low ethanol, but unaffected by either release of 4AA with high ethanol. Dendroctonus valens was significantly attracted to low 4AA and unaffected by high 4AA. Predators appeared to be less inhibited by 4AA than most bark beetles. Although 4AA can deter the attraction of some secondary bark beetles to ethanol in combination with alpha- and beta-pinene, this inhibition could be weakened for certain species by increasing ethanol release rates. 4-Allylanisole may have some utility for managing the behavior of secondary bark beetles sensitive to this compound.

Animals↗

Atypical binding of the neuronal POU protein N-Oct3 to noncanonical DNA targets. Implications for heterodimerization with HNF-3 beta.

The capacity of POU proteins to recognize different DNA sequences and to bind target DNA in the form of monomers, cooperative dimers or heterodimers is important in relation to their transcriptional regulatory properties. The N-Oct3 neuron-specific protein binds to an octamer-like sequence (AAATAATGC) within the (-102/-72) neuronal promoter region of the human aromatic L-amino acid decarboxylase (AADC) gene. In this atypical case the POUh and POUs tetrameric subsites are spaced one nucleotide apart and in switched order as compared with the consensus octamer. Moreover this POU binding motif overlaps the hepatocyte nuclear factor HNF-3 beta binding site (TGCTCAGTAAA) which itself contains a heptamer-like sequence (CTCAGTA). Using the isolated DNA binding domains (DBD) of the two proteins, it is shown that, when binding to this unusual recognition sequence, N-Oct3 either exhibits noncooperative homodimerization or allows the simultaneous binding of the second transcription activator HNF-3 beta. CD studies indicate that the binding of N-Oct3 monomers/dimers and N-Oct3-HNF-3 beta heterodimers to the DNA induces conformational changes of both protein and DNA. Partial proteolysis/MALDI-MS was used in conjunction with molecular modelling to show that the protein conformational change resulting from binary N-Oct3/DNA complex formation occurs within the linker peptide joining the POUs and POUh subdomains. Furthermore, modelling the N-Oct3/HNF-3 beta/DNA ternary complex predicts a nucleotide rearrangement in the overlap region and an interaction between both transcription factors. In the light of our findings, which illustrate both site-dependent and site-independent protein and DNA conformational changes, general implications for the allosteric function of DNA response elements in transcriptional regulation are discussed.

Allosteric Site↗

Transjugular approach to concurrent mitral-aortic and mitral-tricuspid balloon valvuloplasty.

A transjugular approach was successfully used for concurrent mitral-aortic and mitral-tricuspid valvuloplasty in one patient each. This approach simplifies antegrade transvenous aortic valve dilatation in rheumatic aortic stenosis. Advantages obtained by transjugular tricuspid valvuloplasty are easy crossing of the tricuspid valve and stable balloon position, co-axial with the tricuspid orifice.

Adult↗

First branchial groove anomaly.

First branchial groove anomalies are very rare. We report a case of a first branchial groove anomaly presented as an infected cyst in an 11-month-old child. Management of such lesions is complicated because of their close association with the facial nerve. Surgical management must include identification and protection of the facial nerve. Embryology and facial nerve disposition in relation to the anomaly are reviewed.

Branchial Region↗

Genetic variation and intergenerational FMR1 CGG-repeat stability in 100 unrelated three-generation families from the normal population.

In order to identify genetic factors governing expansion of the CGG repeat in the FMR1 gene and to determine what predisposes or causes a normal stable allele to change to an unstable premutation allele, it is essential to study and understand the basis of normal variation. The aim of this study was to investigate genetic variation and intergenerational stability of the FMR1 CGG-repeat region in 100 unrelated three-generation families from the general population (651 meioses). The number of CGG-repeats in the FMR1 gene was determined in all 750 individuals from the 100 families (a total of 1,132 X-chromosomes), and the allele frequencies and variability were analyzed. Thirty-six different alleles (12-60 repeats) were seen with 30 (45.8%) as the most common allele; overall female heterozygosity was 73%. Most (>96%) of the normal array lengths were less than 40 repeats. Fifteen families with at least one allele equal to or greater than 40 repeats (40-60) were identified; in one of these families there was an increase of one triplet repeat during transmission from a mother to son. These findings, together with future molecular analyses, may provide data to test proposed models that attempt to explain the mutational process and the population dynamics of the triplet repeat region of the FMR1 gene, including the transition from normal to unstable alleles, or to test other putative cis-acting sequences that may be involved with instability in the FMR1 gene.

Alleles↗

Distribution of variable vs fixed costs of hospital care.

CONTEXT: Most strategies proposed to control the rising cost of health care are aimed at reducing medical resource consumption rates. These approaches may be limited in effectiveness because of the relatively low variable cost of medical care. Variable costs (for medication and supplies) are saved if a facility does not provide a service while fixed costs (for salaried labor, buildings, and equipment) are not saved over the short term when a health care facility reduces service. OBJECTIVE: To determine the relative variable and fixed costs of inpatient and outpatient care for a large urban public teaching hospital. DESIGN: Cost analysis. SETTING: A large urban public teaching hospital. MAIN OUTCOME MEASURES: All expenditures for the institution during 1993 and for each service were categorized as either variable or fixed. Fixed costs included capital expenditures, employee salaries and benefits, building maintenance, and utilities. Variable costs included health care worker supplies, patient care supplies, diagnostic and therapeutic supplies, and medications. RESULTS: In 1993, the hospital had nearly 114000 emergency department visits, 40000 hospital admissions, 240000 inpatient days, and more than 500000 outpatient clinic visits. The total budget for 1993 was $429.2 million, of which $360.3 million (84%) was fixed and $68.8 million (16%) was variable. Overall, 31.5% of total costs were for support expenses such as utilities, employee benefits, and housekeeping salaries, and 52.4% included direct costs of salary for service center personnel who provide services to individual patients. CONCLUSIONS: The majority of cost in providing hospital service is related to buildings, equipment, salaried labor, and overhead, which are fixed over the short term. The high fixed costs emphasize the importance of adjusting fixed costs to patient consumption to maintain efficiency.

Chicago↗

Catheter-based techniques for closure of coronary fistulae.

This study details different methodologies of percutaneous closure of arteriosystemic and arteriovenous coronary fistula. Seven patients underwent transcatheter intervention of 10 fistulas, with 7 fistulas successfully closed: 6 with embolic coil devices and 1 with a covered stent obstructing the fistula ostium. The major complication encountered was one death as a result of device recoil into a major epicardial vessel. Percutaneous transcatheter closure of coronary fistulas appears to be simple, facile, and effective. However, device recoil into an undesired arterial segment, while irritating in a noncoronary arterial tree, may be catastrophic when occurring in an epicardial coronary artery.

Aged↗