Patency of neck veins following ultrasound-guided percutaneous Hickman line insertion.

PURPOSE: Venous occlusion following permanent central venous catheter (CVC) insertion by open cutdown or the landmark percutaneous technique has been reported between up to 25 %. However, there are no published data on the equivalent rate following ultrasound-guided percutaneous CVC insertion. The purpose of this study was to document the rate of venous occlusion associated with ultrasound-guided percutaneous CVC insertion in children. METHOD: From 1 April 2010 to 1 December 2011, all children having elective or emergency removal of a Hickman line by the vascular access team had a Doppler ultrasound of their neck veins. Only Hickman lines inserted by the ultrasound-guided percutaneous route were included. Internal jugular, innominate and subclavian veins were scanned and recorded as patent, reduced or absent. RESULTS: We identified 100 consecutive children. Median age was 6 years (range 21 days to 16 years). Indication for insertion was chemotherapy (60), parenteral nutrition (15), blood products (12), renal replacement (3) and other indications (10). Three children had absent flow at the time of line removal (median age 4 months, range 3-6 months), with 2 out of 3 requiring removal for infection. The venous occlusion rate following ultrasound-guided insertion of CVC is 3 % in our study. CONCLUSIONS: We conclude that (1) complete venous occlusion is associated with younger age and CVC infection. (2) In our study, the venous occlusion rate of 3 % is significantly lower than the published series of either open cutdown or the landmark technique.

Ultrasound-guided percutaneous insertion of 2.7 Fr tunnelled Broviac lines in neonates and small infants.

BACKGROUND/PURPOSE: Insertion of permanent central venous access (Broviac line) can be a challenge in neonates especially when sites for peripherally inserted central catheters (PICC) have been exhausted. The landmark technique (LT) has been well described for the percutaneous insertion of central lines in neonates but can be associated with significant complications including death. The use of the ultrasound-guided approach for temporary central line access has been reported but as yet there are no reports of the adaptation of the technique for Broviac line insertion in neonates. METHOD: A prospective database records all procedures carried out by the vascular access team and any complications which occur; this database was reviewed from November 2004 to January 2008. RESULTS: A consecutive series of 34 neonates underwent insertion of 36 Broviac lines using the ultrasound-guided percutaneous technique with a 2.7 Fr silastic line and a 3 Fr peel-apart sheath. Median gestational age was 34 weeks (range 24-40), chronological age was 102 days (14-209 days), weight 2.9 kg (0.63-4.1). Successful cannulation occurred in 100% of patients. There were no cases of arterial puncture or perioperative complications due to surgery. CONCLUSION: The ultrasound-guided percutaneous approach for insertion of tunnelled permanent vascular access is safe in neonates with no surgical complications in our series. However, it is a technically demanding procedure to do in neonates and should not be attempted without significant prior experience.

Massive heat-shock polypeptide synthesis in late chicken embryos: convenient system for study of protein synthesis in highly differentiated organisms.

In cultured eucaryotic cells, heat treatments specifically induced the rapid synthesis of the so-called heat-shock polypeptides. To ascertain the physiological importance of this phenomenon for highly differentiated organisms, we attempted to determine whether the heat-shock response occurs in a living endothermic organism at extreme temperatures, and if so, whether the response is organ specific. We developed a procedure to label proteins efficiently in 5- to 18-day-old chicken embryos. Heat-shock polypeptides of identical sizes of 85,000, 70,000, and 25,000 daltons were synthesized predominantly in chicken embryo fibroblasts and in many different organs of 18-day-old embryos at 42.5 to 44 degrees C.

A transgenic mouse model for the detection of cellular stress induced by toxic inorganic compounds.

Transgenic mice for genotoxicity testing have been developed, although no such models have been produced for the evaluation of toxic, nongenotoxic chemical compounds. We have developed a transgenic mouse model for the analysis of toxic inorganic compounds. We engineered a mouse lineage with the human growth hormone (hGH) gene under the control of the human hsp70 promoter, in which a plasma-detectable hGH response can be elicited by exposure to heat shock. In primary cell cultures from these mice, hGH release was observed following treatment with several toxic inorganics. Transgenic mice injected intraperitoneally with sodium arsenite, cadmium chloride, copper sulphate, or methylmercurium chloride showed significant hGH levels in plasma.

Hybrid plasmids carrying part of the Rous sarcoma virus-specific leader sequence.

'Strong-stop' DNA, complementary to the 5'-terminal 101 nucleotides of Rous sarcoma virus genomic RNA and subgenomic mRNAs can be used to isolate RSV-specific mRNA from infected cells. To analyse leader sequences of these mRNAs and to study the mechanism of their translation, relatively large quantities of strong-stop DNA are required. The construction of four plasmids carrying useful strong-stop DNA sequences for mRNA isolation is described. One such hybrid plasmid carries a DNA insertion containing sequences derived from a region starting 42 nucleotides from the 5'-end of RSV RNA, and ending at the tRNATry primer attachment site. Since this plasmid lacks the 20-nucleotide terminal repeat sequence it can be used for the specific isolation of 5'-end fragments of RSV-specific mRNAs and of complementary DNA transcripts of these fragments.

Single and divided doses of penbutolol.

Penbutolol, a nonselective beta-adrenoreceptor antagonist, induced reduction of exercise-induced heartbeats for at least 24 hr after a single 40-mg oral dose, and was equipotent with respect to a 2 X 20-mg regimen over the same period. Ingestion for 7 days did not influence the pharmacodynamics or pharmacokinetics of penbutolol, and there was no cumulation of drug in serum. A relationship was found between the logarithms of measurable serum concentrations of penbutolol and the percentage reduction of total heartbeats. Absorption of oral penbutolol appeared to be reduced when administered in the evening. Since beta-adrenoceptor activity was relatively unchanged between 13 and 24 hr after a single 40-mg dose of penbutolol, there is a possibility that an active metabolite or metabolites may contribute to prolonged duration of action.

High-level, heat-regulated synthesis of proteins in eukaryotic cells.

Plasmids have been constructed in which promoters of 70-kDa heat-shock protein genes (hsp70) of human and Drosophila origin were linked to three different eukaryotic genes encoding human growth hormone (hGH), chicken lysozyme (cL) and a human influenza haemagglutinin (HA). Following transfection into widely divergent eukaryotic cells, the hybrid genes direct the transient, heat-regulated synthesis of the three proteins. hGH and cL are secreted into the medium. A human hsp70-hGH construct was used to establish stable mouse fibroblast lines that are capable of producing and secreting hGH at high levels following heat induction: hGH is secreted at a 500-1200-fold higher rate by heat-treated than by untreated cells.

Orthotopic liver transplantation in patients over 60 years old.

A retrospective examination was performed, including a case control study, of 40 patients aged 60 years and over who underwent liver transplantation at King's College Hospital, London, UK, between 1988 and September 1993. There was no significant difference between elderly patients and younger patients in preoperative condition, intraoperative interventions, or outcome assessed by survival, complication rate, and duration of stay on the intensive care unit. The only significant difference between age groups was the median length of hospital stay, which was 24 days for the elderly versus 20 days for younger patients. We conclude that age up to 70 years should not be a barrier to liver transplantation.

Heat-regulated expression of the hepatitis B virus surface antigen in the human Wish cell line.

The DNA fragment coding for the hepatitis B virus surface antigen (HBsAg) was placed under the control of a human 70 kDa heat-shock protein (hsp70) promotor sequence. This plasmid construct has been used in transfection experiments to establish a stable amnion cell line of human origin (Wish), expressing an HBsAg in a heat-regulated fashion. Post-translational modifications, such as assembly, glycosylation, secretion and production of both major and middle S proteins appear to function normally. In addition, production of HBsAg under various protocols of heat induction is described. After inoculation into nude mice, development of tumours has been observed at the site of injection. Tumour cells, dispersed by means of collagenase or trypsin treatment from excised tumours, and subsequently seeded into Petri dishes, were able to secrete the same quantities of HBsAg after heat induction as were cells of the original cell line.

Use of extracorporeal photochemotherapy in heart transplant recipients during acute rejection: a case study.

Despite the growing availability of improved immunosuppressive agents, acute and chronic rejection episodes remain a major complication in heart transplant recipients. The rejection of allografts is a normal part of the body's response to foreign antigens. The key to controlling this response is to administer a regimen of multiple immunosuppressive drugs. Evidence indicates that by adding extracorporeal photochemotherapy to a standard immunomodulatory regimen, the rejection process can be reversed without significantly increasing patient risk. In this case study we examine extracorporeal photochemotherapy and the care of patients receiving this therapy.

Agreement between three commercially available instruments for measuring short-term heart rate variability.

Numerous instruments are commercially available to measure heart rate variability, yet little is known regarding the agreement between such instruments. The objective of this study is to assess agreement between measures of heart rate variability in three commercially available instruments. Thirty subjects (20 males) of median age 27.5 (range 19-59 years) underwent simultaneous ECG recordings, under three different resting conditions: supine, standing and supine with controlled breathing, using three commercially available analysers. Intraclass correlation coefficients tended to show excellent agreement (lower 95% C.I., R > 0.75) between all instruments under all conditions. However, further analysis of selected measurements using the limits of agreement method revealed large variation in values generated by all instruments. There was also an evidence of systematic bias between one instrument and the remaining two. The latter finding was due to discrepant ECG recording protocols that were unrelated to consistent operator timing. This study demonstrates that measures of HRV generated by the three instruments did not agree well in all cases. Discrepancies were due to the recording protocols of the systems. This may lead to incomparable results between instruments. It is therefore recommended that: (a) if different instruments are used in the same study or (b) multi-centre study designs are planned or (c) heart rate variability results are discussed with reference to studies using other instruments, levels of agreement need to be reported to ensure comparability.

Reliability of three commercially available heart rate variability instruments using short-term (5-min) recordings.

AIM: To assess the reliability of heart rate variability (HRV) measures made by three commercially available analysers in healthy subjects. METHODS: Twenty-nine volunteers (20 males, mean age 35 +/- 13 years and nine females, mean age 29 +/- 11 years) underwent repeated HRV measures under three conditions: lying supine, standing, lying supine with controlled breathing. HRV was measured simultaneously by three instruments. Reliability was assessed statistically by calculating coefficient of variation (CV), intraclass correlation coefficient (ICC) and limits of agreement (LoA). RESULTS: A wide range of values were found for CV (1-235%) and ICC (R = 0.16-0.99) dependent on the HRV measure assessed and the position in which the measurement was made. For the most part the analysers gave similar values in each condition. The values for CV and ICC were high but within the range reported in the literature. Values for LoA were also high and showed a wide range of values. CONCLUSIONS: The similarity in measures between systems indicates that biological variation and experimental error play a major role in determining the repeatability of HRV measurements. It is therefore recommended that population-specific reliability coefficients should be published where possible and that authors should take into account the reliability of measures when making sample size calculations.

Abdominal aortic aneurysms before and after endograft implantation: evaluation by computed tomography.

The evaluation of patients with abdominal aortic aneurysms for endograft candidacy and their follow-up after treatment are heavily dependent on radiologic imaging. Factors never considered during conventional open repair have become crucial to patient selection and procedural success, and the new and developing nature of the field of endovascular repair necessitates close surveillance of these devices after deployment. Computed tomography (CT) has emerged as the single most effective imaging tool for the preprocedural assessment and subsequent follow-up of these patients. This article outlines the technical parameters for obtaining pre- and postoperative CT examinations in endograft patients and discusses the important imaging findings.

Lessons from the wild turkey.

Fifty years ago, the American wild turkey survived in isolated, small populations. Now an estimated 5.6 million birds are spread across the continental United States (minus Alaska) and Ontario, Canada.

Anaesthetic outcome and predictive risk factors in children with mediastinal tumours.

PURPOSE: The aims were to identify and test the significance of specific factors associated with risks for anaesthesia in children with mediastinal tumours. PATIENTS AND METHOD: Clinical information was retrospectively collected from the records of 63 children presented with mediastinal tumour (1964-2002) in a regional Paediatric Oncology centre and correlated with the type and outcome of anaesthesia, using non-parametric analyses. RESULTS: Thirteen patients had local anaesthesia or sedation for diagnostic procedures and none developed any complication. Fifty children received general anaesthesia (GA) for diagnostic investigations or tumour resection. Two patients were excluded from the analysis because of treatment prior to GA. Problems with intubation, ventilation and cardiovascular collapse were encountered in 7 of 48 (15%) patients and this resulted in tracheostomy in one patient and death in 2 other cases. When compared with the 41 uncomplicated cases, the presence of at least 3 respiratory symptoms/signs, tracheal and vascular compression, and infection significantly increased the risk of GA. Of these, tracheal compression remained the strongest predictive factor. CONCLUSIONS: Decision to postpone GA should be considered if all these risk factors (tracheal compression, vascular compression, the presence of at least three respiratory symptoms/signs) are present in the same patient.