Characterisation of H2S···CuCl and H2S···AgCl isolated in the gas phase: a rigidly pyramidal geometry at sulphur revealed by rotational spectroscopy and ab initio calculations.

Pure rotational spectra of the ground vibrational states of eight isotopologues of H(2)S···CuCl and twelve isotopologues of H(2)S···AgCl have been analysed allowing rotational constants and hyperfine coupling constants to be determined. The molecular structures have been determined from the measured rotational constants and are presented alongside the results of calculations at the CCSD(T) level. Both molecules have C(s) symmetry at equilibrium and are pyramidal at the sulphur atom. The chlorine, metal, and sulphur atoms are collinear while the local C(2) axis of the hydrogen sulphide molecule intersects the axis defined by the heavy atoms at an angle, φ = 74.46(2)° for Cu and φ = 78.052(6)° for Ag. The molecular geometries are rationalised using simple rules that invoke the electrostatic interactions within the complexes. Centrifugal distortion constants, Δ(J), and nuclear quadrupole coupling constants, χ(aa)(Cu) and χ(aa)(Cl) for H(2)S···CuCl are presented for the first time. The geometry of H(2)S···AgCl is determined with fewer assumptions and greater precision than previously.

18F-FDG dual-headed gamma camera PET in detection of axillary nodal disease in patients with large or locally advanced breast cancer: possible alternative staging of axilla.

Positron emission tomography (PET) has been used in staging the axilla. Gamma Camera PET (GCPET) is a cost effective alternative, but poorly studied. The aim of this study was to assess GCPET in demonstrating metastatic deposits in axillary nodes in patients with a high likelihood of nodal disease. Twenty-seven women with large (T2, T3 or T4) or advanced breast cancer (N1, N2 or M1) were recruited. All patients underwent axillary lymph node removal or biopsy (fine needle aspiration cytology (FNAC) or core cut) and whole body GCPET imaging. Images were reported anonymously and compared with the histological findings. Twenty-one patients proceeded to surgery and 10 had tumour-involved axillary nodes; GCPET was positive in 8 of these. The remaining 6 patients underwent core cut or FNAC of the axillary nodes, 2 of which contained a tumour. GCPET was positive in both cases. Thus, the diagnostic values were: sensitivity 83%, specificity 100%, positive predictive value 100%, negative predictive value 88% and accuracy 93%. In conclusion, GCPET is a reliable method and can be performed in a district general hospital and detecting disease in axillary nodes in certain patients, possibly obviating the need for surgery.

Our inability to predict thromboembolic events after prosthetic valve surgery.

BACKGROUND AND AIM OF THE STUDY: Thromboembolic and bleeding complications detract from outcome for patients with prosthetic heart valves. The study aim was to investigate whether measurement of coagulation activation markers and transcranial Doppler ultrasound microembolic signals (MES) could identify patients at subsequent higher risk of thromboembolism or bleeding events. METHODS: A total of 526 patients (mean age 66 years; 266 males, 260 females) who underwent elective valve replacement surgery was enrolled between April 1999 and October 2002. Clinical assessment and blood sampling for coagulation activation markers was performed preoperatively and at three and 12 months postoperatively. Transcranial Doppler MES were recorded in the first 144 patients. Status was reviewed between 21st April and 9th June 2005, with 99.4% follow up. RESULTS: Among patients, 62% had an aortic valve replaced, and mechanical valves constituted 60% of all implants. The mean follow up was 3.61 years; total follow up was 1,899.2 patient-years (pt-yr). In total, 115 patients died, while 61 experienced a total of 80 thromboembolic events: linearized event rates were 3.94% (mechanical valves) and 4.4% (bioprostheses). There was no difference between mitral and aortic implants, or among bileaflet, tilting-disc mechanical and porcine valves. Atrial fibrillation was not influential. Coagulation activation markers were not associated with thromboembolic events, except for an elevated von Willebrand factor (vWF), which was associated with a five-fold increase in embolic event rate. Fifty-one patients experienced 59 bleeding events; eight patients experienced multiple events. Linearized event rates were 3.37% (mechanical valves) and 2.49% (bioprostheses). The INR was suboptimal in 44-58% of patients. Transcranial Doppler MES were not associated with blood coagulation markers or thromboembolic events. CONCLUSION: Coagulation activation markers (except vWF) and MES did not predict thromboembolic events in valve replacement patients. Thromboembolic and bleeding event rates for West of Scotland patients generally exceeded reported rates: suboptimal anticoagulation appeared common and most likely influenced thromboembolic and bleeding event rates more than any other factor.

A pilot randomised, open, uncontrolled, clinical study of two dosages of St John's wort (Hypericum perforatum) herb extract (LI-160) as an aid to motivational/behavioural support in smoking cessation.

There is an association between smoking and depression, yet the herbal antidepressant St John's wort (Hypericum perforatum L.; SJW) herb extract has not previously been investigated as an aid in smoking cessation. In this open, uncontrolled, pilot study, 28 smokers of 10 or more cigarettes per day for at least one year were randomised to receive SJW herb extract (LI-160) 300 mg once or twice daily taken for one week before and continued for 3 months after a target quit date. In addition, all participants received motivational/behavioural support from a trained pharmacist. At 3 months, the point prevalence and continuous abstinence rates were both 18%, and at 12 months were 0%. Fifteen participants (54%) reported 23 adverse events up to the end of the 3-month follow-up period. There was no statistically significant difference in the frequency of adverse events for participants taking SJW once or twice daily (p > 0.05). Most adverse events were mild, transient and non-serious. This preliminary study has not provided convincing evidence that a SJW herb extract plus individual motivational/behavioural support is likely to be effective as an aid in smoking cessation. However, it may be premature to rule out a possible effect on the basis of a single, uncontrolled pilot study, and other approaches involving SJW extract may warrant investigation.

Mitral valve replacement with mechanical or bioprosthetic valve.

A presentation on the technique of mitral valve replacement is shown: exposure and excision of the diseased mitral valve is demonstrated along with the use of sub-annular and supra-annular interrupted suture techniques for securing biological and mechanical mitral prostheses. A brief overview of the literature is presented.

A comparison of 18F-FDG gamma camera PET, mammography and ultrasonography in demonstrating primary disease in locally advanced breast cancer.

BACKGROUND: Positron emission tomography (PET) imaging using [18F]fluorodeoxyglucose (18F-FDG) is recognized to have a major role in oncological imaging. Over recent years there has been a steady increase in the use of gamma camera PET (GCPET) systems as these are less expensive than dedicated PET scanners and facilitate the full range of nuclear medicine imaging. However, there is ongoing debate about their application and usefulness in the management of oncological patients. OBJECTIVES: To assess the feasibility of GCPET in a nuclear medicine department in a district general hospital remote from a cyclotron, compared with other imaging modalities in demonstrating disease in patients with large or locally advanced breast cancer. METHODS: 18F-FDG was transported by road from a production unit 100 miles from the imaging department. Twenty-five patients (mean age 68 years) with primary breast tumours measuring > or =20 mm on clinical examination were studied. All patients underwent triple assessment prior to PET imaging with an ADAC Solus camera with molecular coincidence detection capability. Histopathology was obtained in 20 cases following surgery. RESULTS: GCPET detected 24/25 primary breast tumours (sensitivity 96%). This compared with 22/25 (88%) for ultrasound and 15/25 (60%) for mammography. The lesion missed by PET was a grade 1 tumour, 8 mm in size. CONCLUSION: In this pilot study GCPET has been shown to be feasible in a district general hospital, enabling a limited on-site PET imaging service to be provided. In the cases studied it was more sensitive than mammography or ultrasonography. GCPET may provide additional information that could be important in planning the management of some patients with breast cancer.

Erythrocyte-containing versus crystalloid cardioplegia in the rat: effects on myocardial capillaries.

BACKGROUND: The purpose of this study was to investigate the effects of crystalloid and erythrocyte-containing cardioplegia on capillary morphology of the isolated erythrocyte-perfused rat heart. METHODS: Hearts from adult Sprague-Dawley rats were perfused throughout with resuspended sheep erythrocytes and subjected to the following protocols (n = 6, all groups): (1) 15 minutes nonworking and 30 minutes working heart mode (control; group 1); (2) as for group 1, with 30 minutes erythrocyte-containing (BL) or crystalloid (CR) cardioplegic arrest without reperfusion (groups 2BL and 2CR); (3) as for group 2, with 30 minutes nonworking reperfusion (groups 3BL and 3CR); and (4) as for group 3, with 30 minutes working heart mode (groups 4BL and 4CR). After each protocol troponin I from coronary effluent was measured. Corrosion casts were then made of the coronary microvasculature. Cast density was calculated as cast volume per left ventricular dry weight. Casts also underwent scanning electron microscopy. Analysis was by analysis of variance. Values are mean +/- standard deviation. RESULTS: Prearrest working heart coronary flow averaged 15.1 +/- 4.7 mL/min without any differences among groups. Coronary flow in group 4 working hearts was the same before and after either cardioplegia. Cardiac outputs were similarly consistent in all groups. Cast density in group 1 (control) was 9.60 +/- 1.17 x 10(-2) mm3/mg. It was unaltered by erythrocyte-containing cardioplegia, but after crystalloid cardioplegia (group 2CR), it was 6.52 +/- 0.93 x 10(-2) mm3/mg (p = 0.0001 versus group 1 and p = 0.0007 versus group 2BL). With 30 minutes of nonworking reperfusion (group 3CR, there was slight improvement in cast density at 7.60 +/- 0.90 x 10(-2) mm3/mg (p = 0.0072 versus group 1; p = 0.0242 versus group 3BL). No further improvement was seen in group 4CR. Electron micrographs showed circumferential angularities or narrowings in crystalloid-perfused, arrested hearts, consistent with ischemic damage. Troponin I rose significantly after reperfusion in all groups, but it was higher in crystalloid-perfused, arrested hearts: 0.054 +/- 0.013 microg/L versus 0.024 +/- 0.017 microg/L (p = 0.0273). CONCLUSIONS: Erythrocyte-containing cardioplegia maintained capillary density and morphology. Crystalloid cardioplegia produced capillary loss, visible abnormalities, and higher troponin I release. These hearts may be more vulnerable to myocardial damage during reperfusion than hearts perfused with erythrocyte-containing cardioplegic solution.