Abnormal cardiac conduction in a septic patient: incidental finding or cause for concern?

A 64-year-old male presents to the emergency department in acute respiratory distress. He gives a limited history of progressive shortness of breath of one week's duration and several episodes of sudden unexplained syncope. There was no history of chest pain, palpitations or localising symptoms of infection. He takes no regular medications.

The making of indigenous vascular prosthesis

Background & objectives:

Vascular illnesses are on the rise in India, due to increase in lifestyle diseases and demographic transition, requiring intervention to save life, organ or limbs using vascular prosthesis. The aim of this study was to develop indigenous large diameter vascular graft for treatment of patients with vascular pathologies.

Methods:

The South India Textile Research Association, at Coimbatore, Tamil Nadu, India, developed seamless woven polyester (Polyethylene terephthalate) graft at its research wing. Further characterization and testing followed by clinical trials were conducted at Sree Chitra Tirunal Institute for Medical Sciences and Technology, Thiruvananthapuram, Kerala, India. Fifteen in vivo experiments were carried out in 1992-1994 in pigs as animal model. Controlled (phase I) clinical trial in ten patients was performed along with control graft. Thereafter, phase II trial involved 22 patients who underwent multi-centre clinical trial in four centres across India.

Results:

Laboratory testing showed that polyester graft was non-toxic, non-leeching and non-haemolytic with preserved long-term quality, further confirming in pigs by implanting in thoracic aorta, comparable to control Dacron grafts. Perigraft incorporation and smooth neointima formation which are prime features of excellent healing characteristics, were noted at explantation at planned intervals. Subsequently in the phase I and II clinical trials, all patients had excellent recovery without mortality or device-related adverse events. Patients receiving the test graft were followed up for 10 and 5 years, respectively. Serial clinical, duplex scans and CT angiograms performed periodically confirmed excellent graft performance.

Interpretation & conclusions:

Indigenously developed Chitra vascular graft was comparable to commercially available Dacron graft, ready for clinical use at affordable cost to patients as against costly imported grafts.

Increasing thyroid cancer incidence in Queensland, Australia 1982-2008 - true increase or overdiagnosis?

BACKGROUND

Thyroid cancer incidence has been increasing worldwide. Some suggest greater ascertainment of indolent tumours is the only driver, but others suggest there has been a true increase. Increases in Australia appear to have been among the largest in the world, so we investigated incidence trends in the Australian state of Queensland to help understand reasons for the rise.

METHODS

Thyroid cancers diagnoses in Queensland 1982-2008 were ascertained from the Queensland Cancer Registry. We calculated age-standardized incidence rates (ASR) and used Poisson regression to estimate annual percentage change (APC) in thyroid cancer incidence by socio-demographic and tumour-related factors.

RESULTS

Thyroid cancer ASR in Queensland increased from 2·2 to 10·6/100 000 between 1982 and 2008 equating to an APC of 5·5% [95% confidence interval (CI) 4·7-6·4] in men and 6·1% (95% CI 5·5-6·6) in women. The rise was evident, and did not significantly differ, across socio-economic and remoteness-of-residence categories. The largest increase seen was in the papillary subtype in women (APC 7·9%, 95% CI 7·3-8·5). Incidence of localized and more advanced-stage cancers rose over time although the increase was greater for early-stage cancers.

CONCLUSION

There has been a marked increase in thyroid cancer incidence in Queensland. The increase is evident in men and women across all adult age groups, socio-economic strata and remoteness-of-residence categories as well as in localized and more advanced-stage cancers. Our results suggest 'overdiagnosis' may not entirely explain rising incidence. Contemporary aetiological data and individual-level information about diagnostic circumstances are required to further understand reasons for rising thyroid cancer incidence.

Assessment of blood clot formation and platelet receptor function ex vivo in patients with primary Sjogren's syndrome

OBJECTIVES

Primary Sjögren's syndrome (pSS) shares clinical features and pathogenetic mechanisms with systemic lupus erythematosus (SLE). SLE is associated with an increased thromboembolic risk; however, it is unclear whether pSS patients are susceptible to thromboembolic diseases. In this study, we examined ex vivo blood clot formation (clot strength, rates of clot formation and lysis) in pSS using thromboelastography (TEG) and platelet aggregation to common agonists using multiple electrode aggregometry (MEA). We also investigated the relationship between TEG/MEA parameters and clinical/laboratory features of pSS.

DESIGN

Case control.

SETTING

Secondary care, single centre.

PARTICIPANTS

34 pSS patients, 11 SLE patients and 13 healthy volunteers (all women) entered and completed the study.

PRIMARY OUTCOMES

TEG and MEA parameters between three subject groups.

SECONDARY OUTCOMES

The relationships between TEG/MEA and clinical/laboratory parameters analysed using bivariate correlation analysis with corrections for multiple testing.

RESULTS

All TEG and MEA parameters were similar for the three subject groups. After corrections for multiple testing, interleukin (IL)-1α and Macrophage inflammatory proteins (MIP)-1α remain correlated inversely with clot strength (r=-0.686, p=0.024 and r=-0.730, p=0.012, respectively) and overall coagulability (r=-0.640, p=0.048 and r=-0.648, p=0.048). Stepwise regression analysis revealed that several cytokines such as MIP-1α, IL-17a, IL-1α and Interferon (IFN)-γ may be key predictors of clot strength and overall coagulability in pSS.

CONCLUSIONS

Clot kinetics and platelet receptor function are normal in pSS. Several cytokines correlate with clot strength and overall coagulability in pSS.

Use of the AorfixTM stent graft in patients with tortuous iliac anatomy

AIM

Iliac limb occlusion following endovascular repair (EVAR) may result in limb threatening acute ischemia. The incidence is reported at up to 10% and is known to be influenced by iliac angulation and kinking of the stent graft. The aim of this study was to evaluate the performance of the AorfixTM graft in tortuous iliac anatomy and examine the impact of the graft on the rate of iliac limb thrombosis following EVAR in a single UK centre

METHODS

We performed a retrospective review of all EVAR performed from May 1998 to May 2010. From November 2007, patients with highly angulated iliac anatomy were treated with the AorfixTM(Lombard) stent graft, or when a ZenithTM(Cook) main body was chosen, the AorfixTM iliac limbs were used with the ZenithTM(Cook) device. We compared the rate of iliac limb occlusions before (group 1) and after (group 2) the adoption of this policy.

RESULTS

Two hundred and sixty seven patients underwent EVAR (group 1 n=129; group 2 n=138). In group 1, eight patients had a unilateral iliac limb occlusion (6.2%). Six of the patients had >90 degrees iliac angulation, one had an unrecognised limb stenosis, and one patient had the stent landed in the external iliac. In group 2 there were no limb occlusions. Of the 138 patients, 25 had iliac angulation of >90 degrees . Of these 25, eighteen were treated with the AorfixTM stent graft system because of iliac angulation, and 7 were treated with AorfixTM legs and ZenithTM bodies.

CONCLUSION

The rate of early iliac limb occlusion following EVAR in patients with angulated iliac anatomy can be substantially reduced by using the flexible Aorfix stent graft system.

The advantages of Aorfix for endovascular repair of abdominal aortic aneurysm

AIM

The aim of this paper was to review the use of the Aorfix stent-graft in the endovascular repair of abdominal aortic aneurysms and to report the early results of a multicenter study conducted on patients receiving this endograft.

METHODS

A retrospective review of 40 patients having the Aorfix stent-grafts for their aneurysm repair was undertaken at two centers. Patient notes and imaging findings were used to identify technical success, 30 day mortality, rupture rates during follow-up, postoperative complications including endoleaks, graft migration and any secondary interventions.

RESULTS

All patients were treated successfully. Four patients required the use of proximal extensions due to severe neck angulation. There were neither deaths nor secondary interventions in the follow-up period. No incidence of graft migration or endoleaks was identified at 12 months after the procedure.

CONCLUSIONS

Early data with the Aorfix stent-graft shows favorable results. The device's flexible design allows safe and accurate aneurysm sac exclusion in patients with highly challenging anatomy. This is likely to increase the number of patients considered suitable for endovascular aneurysm repair, who were previously excluded from this type of treatment and also reduce the levels of endoleaks.

Measuring Newtonian viscosity from the phase of reflected ultrasonic shear wave

In this paper, an acoustic shear impedance model is employed to obtain a relation between the viscosity of a Newtonian fluid and phase characteristics of ultrasonic shear wave reflection from a solid-fluid interface. The phase and magnitude of the reflection coefficient can be decoupled in this model. The decoupling allows an independent relation between the acoustic shear impedance (viscosity-density product) and phase of the reflection coefficient. The model was experimentally verified for different fluid-solid combinations. Comparison of the results with the commonly used absolute reflection coefficient method demonstrates that phase measurement provides improved measurements.

Addition of enemas to oral lavage preparation for colonoscopy is not necessary

To evaluate whether the addition of enemas to oral electrolyte lavage is helpful for colonoscopic preparation, we conducted a prospective, randomized, observer-blinded trial to compare oral lavage plus enemas with oral lavage alone. The quality of preparation, mucosal visualization, and the volume of retained colonic fluid did not differ between the two groups. Twenty-two percent of the patients in the group who received oral lavage plus enemas compared with 12% of the patients in the group that only received oral lavage stated that they would refuse to repeat the preparation for future colonoscopic examination. Seventeen percent of the patients in the group that received oral lavage plus enemas demonstrated anorectal trauma or inflammation compared with only 5% in the group that received oral lavage alone (p = 0.09). These results indicate that the addition of enemas to oral lavage preparation for colonoscopic evaluation cannot be routinely recommended. However, enemas may be considered on an individual basis in the occasional patient unable to consume the complete oral lavage or in whom residual stool is found during colonoscopic evaluation after oral lavage preparation.

Early diagnosis of cytomegalovirus hepatitis in liver transplant recipients: role of immunostaining, DNA hybridization and culture of hepatic tissue

Immunostaining techniques that use a monoclonal antibody against an early cytomegalovirus antigen or a polyclonal antibody, in situ DNA hybridization and inoculation of cell cultures for the detection of cytomegalovirus from liver biopsy specimens were studied in 20 liver transplant patients with cytomegalovirus hepatitis, as defined by histological criteria. A total of 108 liver biopsy specimens from 20 patients with a diagnosis of cytomegalovirus hepatitis (obtained per protocol at 7, 21, 90, and 180 days or whenever liver dysfunction occurred), which had previously been examined histologically and in cell culture, were again studied by recutting the liver tissue for histological examination, DNA hybridization and immunostaining with monoclonal or polyclonal antibodies to cytomegalovirus. In 5 of 20 patients, the diagnosis of cytomegalovirus hepatitis could have been made earlier (mean = 9.6 days) by immunostaining with a monoclonal antibody. Of 47 biopsy specimens with cytomegalovirus inclusion bodies, the sensitivity and specificity of the diagnostic procedures were immunostaining with monoclonal antibody (84% and 90%) and polyclonal antibody (72% and 97%), in situ DNA hybridization (72% and 100%) and cell culture detection (52% and 95%), respectively. Immunostaining with a monoclonal antibody against an early CMV antigen frequently detected cytomegalovirus infection in the liver allograft earlier than identification of typical histological inclusion bodies. DNA in situ hybridization was less sensitive than other techniques but highly specific; cytomegalovirus cell culture lacked sensitivity compared with the other procedures.

Diminished survival in asymptomatic primary biliary cirrhosis. A prospective study

Data from 73 asymptomatic patients with primary biliary cirrhosis were analyzed to determine clinical course and long-term survival. Of these, 44 entered a D-penicillamine treatment trial; 29 qualified but chose not to participate. Median follow-up was 7.6 yr (range, 2.8-12.2 yr). Liver biopsy at the initial visit showed advanced disease (fibrosis, cirrhosis) in 61% of the patients. During prospective clinical follow-up, which was available for 37 of the 44 study patients, one or more symptoms of liver disease developed in 33 (89%); esophageal varices were found in 15 (41%), and histologic progression to cirrhosis was found in 20 (67%) of the 30 precirrhotic patients. Significant (p less than 0.01) biochemical progression was reflected by a decrease in mean serum albumin concentrations and an increase in mean serum bilirubin levels in 32 patients followed for 4-6 yr. Survival data were available for all 73 patients; 17 died (11 secondary to liver failure), and 1 underwent liver transplantation. These patients had a 4-fold increase in mortality rate (p less than 0.001) compared with the U.S. population matched for age, race, and sex.

Primary sclerosing cholangitis with normal serum alkaline phosphatase activity

We report 12 cases of primary sclerosing cholangitis (confirmed by cholangiography) in which the serum alkaline phosphatase activity was normal. The enzyme activity remained normal during follow-up in 7 cases and fluctuated in 5 cases (it returned to normal in 4). The presence of advanced histologic stage (fibrosis/cirrhosis) with marked cholangiographic changes in 4 patients establishes that cirrhotic-stage primary sclerosing cholangitis can occur without a concomitant increase in serum alkaline phosphatase activity. Therefore, primary sclerosing cholangitis may exist in an occult state without symptoms or increase in serum alkaline phosphatase activity. Our findings suggest that primary sclerosing cholangitis may be more prevalent than realized, especially in patients who have inflammatory bowel disease. A normal value for serum alkaline phosphatase activity should not preclude further investigation for primary sclerosing cholangitis in patients with inflammatory bowel disease when symptoms or signs suggest liver disease.

An attempt to identify amino groups of Naja naja siamensis neurotoxin that interact with acetylcholine receptor by a comparison of their reactivities in free and receptor-bound neurotoxin

An attempt to identify amino groups of Naja naja siamensis neurotoxin that interact with acetylcholine receptor by a comparison of their reactivities in free and receptor bound neurotoxin. Toxicon 21, 219-229, 1983--Free Naja naja siamensis neurotoxin was acetylated with non-radioactive and acetylcholine receptor-bound neurotoxin with radioactive acetic anhydride. The toxins from the two experiments were combined and the monoacetyl derivatives isolated by chromatography on Bio-Rex 70. The yields were determined by spectrophotometry and scintillation counting. To localize the acetyl group, a radioactive monoacetyl toxin was oxidized with performic acid, digested with trypsin and a peptide with the radioactive acetyl group was isolated by gel filtration on Sephadex G-25 and high voltage paper electrophoresis. Amino acid analysis indicated from which part of the molecule the peptide was derived. In free toxin, Ac-Lys 23 and 49 account for 56% and 12%, respectively, of the monoacetyl derivatives, and in bound toxin for only 25% and 8%. Lys 49 is as reactive as Ile 1 in free toxin and 50-150% more reactive than Lys 69, 35 and 12, but it has the lowest reactivity in bound toxin, being only about half as reactive as any of these three residues. The large decrease in reactivity of Lys 23 and 49 indicates that they interact with the receptor. The proximity of the receptor makes them less accessible to acetic anhydride. The reactivities are compared to that of Lys 12, which in free toxin has the least reactive amino group. The yield of Ac-Lys 23 relative to that of Ac-Lys 12 drops from 12.4 to 1.5, or by 88%, Lys 49, 2.6 and 0.5 (81%); Ac-Ile 1, 2.6 and 1.1 (58%); Ac-Lys 69, 1.9 and 0.9 (53%); Ac-Lys 35, 1.8 and 1.0 (44%). The drop in reactivity relative to that of Lys 12 indicates a real decrease, provided that Lys 12 does not become more reactive in bound toxin. This is unlikely, since sequence homology shows that Lys 12 corresponds to Lys 15 of the neurotoxin oxiana II of Naja naja oxiana, a residue known to interact with the receptor. Sequence homology also supports the conclusion that the drop in the reactivity of Ile 1 has the same cause. The receptor-binding region of the siamensis toxin is rather large, containing the residue Lys 23 and 49, Ile 1 and probably also Lys 69 and 35.

Impairment of cognitive function associated with hydroxyamylobarbitone accumulation in patients with renal insufficiency

1. Sodium amylobarbitone was given by intravenous infusion to six patients with chronic renal insufficiency and to six healthy volunteer subjects. Serum concentrations of amylobarbitone and its major metabolite hydroxyamylobarbitone were measured by a gas chromatograph method.2. The serum concentrations of amylobarbitone were consistently lower in the patient group than in the control group and the concentration half time was shorter (0.10>P>0.05); the 48 h urinary excretion of hydroxyamylobarbitone was reduced (P<0.001) and the serum concentrations of hydroxyamylobarbitone were consistently raised.3. When two patients were given 200 mg of sodium amylobarbitone daily over five consecutive days the serum concentration of hydroxyamylobarbitone rose steadily to a maximum of about 8 mug/ml. The serum concentrations in two healthy control subjects did not exceed 0.5 mug/ml.4. Three parallel tests of cognitive function (Otis matched test forms A, B and C) were given to 16 control patients and to 12 amylobarbitone-treated patients. Significant impairment of performance was observed in test B (P<0.001) at a time when amylobarbitone only could be detected in the patients' serum, and in test C (P<0.001) when amylobarbitone concentrations were very low (0.52+/-0.08 mug/ml+/-SEM) but hydroxyamylobarbitone concentrations were still high (3.30+/-1.23, mug/ml+/-SEM).5. There was a strong (r=-0.71) and significant (P<0.01) negative correlation between the performance in test C and the serum concentration of hydroxyamylobarbitone. It is concluded that hydroxyamylobarbitone has cerebral depressant effects in man.

The kinetics of amylobarbitone metabolism in healthy men and women

1. Sodium amylobarbitone (3.54 mg/kg) was given by intravenous injection to seven healthy men and nine healthy women who were not receiving other drugs. Serum amylobarbitone and urine hydroxyamylobarbitone concentrations were measured by gas-liquid chromatography. There was no significant difference between the groups either in the serum amylobarbitone concentration/time curves or in the urinary excretion of hydroxyamylobarbitone.2. The serum amylobarbitone concentration decayed over 48 h as a double exponential function of time; the first exponential component had a mean half-time of 0.6 h (males 0.56 +/- 0.06 h, females 0.62 +/- 0.08 h, +/- S.E.) and the second exponential component had a mean half time of 21 h (males 22.7 +/- 1.6 h, females 20.0 +/- 1.0 h, +/- S.E.).3. The urinary excretion of hydroxyamylobarbitone over 48 h accounted for 34% of the dose (males 33.8 +/- 3.2%, females 35.2 +/- 3.0%, +/- S.E.). One male and two female subjects excreted hydroxyamylobarbitone partly as a conjugate which was readily hydrolysed in acid.4. An elimination constant (k(el)) derived from the serum concentration/time curve by the application of a two compartment model was approximately proportional to beta (h(-1)), the rate constant of the second exponential component. There was a positive correlation (r=0.78, P<0.001) between beta and the mean rate of urinary excretion of hydroxyamylobarbitone during the 24 to 48 h period.

The use of tadpoles of Bufo melanostictus (Schneider), Rhacophorus leucomystax maculatus (Gray) and Uperodon sp. in the bioassay of aflatoxins

The action of di-isopropylfluorophosphate and three p-nitrophenylalkylethyl phosphonates on the biochemical changes induced in leucocytes treated with leucocidin has been studied.

Phosphonates enhance the secretion of β-glucuronidase, the accumulation of calcium and the production of orthophosphate when leucocidin is in suboptimal amounts but not when it is in excess. The inactivation of leucocidin by the leucocyte and the stimulation by leucocidin of the acetyl phosphatase of the leucocyte cell membrane are not affected. Phosphonates do not enhance the secretion of β-glucuronidase when it is induced by streptolysin O or vitamin A.

These actions of phosphonates suggested they might act on the potassium pump of the cell membrane and it has been found that phosphonates inhibit the re-accumulation of potassium by leucocytes.

It is suggested that phosphonates inhibit the potassium pump by competing for a phosphorylation site and that the enhancement of leucocidin arises because the cell is prevented from reversing the structural change induced by leucocidin.

The relevance of these observations to the inhibition of chemotaxis is discussed.