Ease of access is a principal factor in the frequency of paracetamol overdose

Background  

In Ireland, 30% of non-fatal overdoses involve paracetamol.     

Infectious diseases. 6: Sexually transmitted infections: new diagnostic approaches and treatments

1. Commercially available nucleic acid amplification assays (eg, polymerase or ligase chain reaction) are now the "gold standard" tests for genital chlamydial infection and also have a role in screening for gonococcal infection. 2. Single-dose oral antibiotics are available for treatment of Chlamydia trachomatis, Neisseria gonorrhoeae and Trichomonas vaginalis infections. 3. Strains of N. gonorrhoeae in urban Australia are often penicillin resistant, while strains from South East Asia and those in homosexually active men may show high-level resistance to quinolones. 4. Imiquimod, a novel immune-response modifier, is now available for effective, safe, self-administered treatment of genital warts. 5. The Pap smear remains the cornerstone of screening for precursor lesions of cervical cancer, but human papillomavirus genotyping may have a role in clinical decision-making for women with equivocal or early precancerous lesions. 6. Treatment of primary genital herpes changes the clinical course, and long-term suppressive therapy is effective for those with multiple recurrences. New technologies have made diagnosis and screening easier for patients and clinicians     

Use of CT Hounsfield unit density to identify ablated tumor after laparoscopic radiofrequency ablation of hepatic tumorsrid=""id=""Presented at the annual meeting of the Society of American Gastrointestinal Endoscopic Surgeons (SAGES), Atlanta, Georgia, USA, 29 March–1 April 2000

Background: When attempting to interpret CT scans after radiofrequency thermal ablation (RFA) of liver tumors, it is sometimes difficult to distinguish ablated from viable tumor tissue. Identification of the two types of tissue is specially problematic for lesions that are hypodense before ablation. The aim of this study was to determine whether quantitative Hounsfield unit (HU) density measurements can be used to document the lack of tumor perfusion and thereby identify ablated tissue. Methods: Liver spiral CT scans of 13 patients with 51 lesions undergoing laparoscopic RFA for metastatic liver tumors within a 2-year time period were reviewed. HU density of the lesions as well as normal liver were measured pre- and postoperatively in each CT phase (noncontrast, arterial, portovenous). Statistical analyses were performed using Student's paired t-test and ANOVA. Results: Normal liver parenchyma, which was used as a control, showed a similar increase with contrast injection in both pre- and postprocedure CT scans (56.4 ± 2.4 vs 57.1 ± 2.4 HU, respectively; p= 0.3). In contrast, ablated liver lesions showed a preablation increase of 45.7 ± 3.4 HU but only a minimal postablation increase of 6.6 ± 0.7 HU (p < 0.0001). This was true for highly vascular tumors (neuroendocrine) as well as hypovascular ones (adenocarcinoma). Conclusions: This is the first study to define quantitative radiological criteria using HU density for the evaluation of ablated tissues. A lack of increase in HU density with contrast injection indicates necrotic tissue, whereas perfused tissue shows an increase in HU density. This technique can be used in the evaluation of patients undergoing RFA. Received: 1 March 2000/Accepted: 4 April 2000/Online publication: 9 August 2000     

Local Recurrence After Laparoscopic Radiofrequency Thermal Ablation of Hepatic Tumors

Background: Since we first described laparoscopic radiofrequency ablation (LRFA) of liver tumors, several reports have documented technical and safety aspects of this procedure. Little is known, however, about the long-term follow-up of such patients.Methods: From January 1996 to February 1999, we performed LRFA on 250 liver tumors in 66 patients. Triphasic spiral computed tomographic scanning was obtained preoperatively and at 1 week, and every 3 months postoperatively. Lesion diameter was measured in the x- and y-axes and the volume estimated; 181 lesions in 43 patients for whom computed tomographic scans available were included in the study. The tumor types were as follows: 64 metastatic adenocarcinomas, 79 neuroendocrine metastases, 27 other metastases, and 11 primary liver tumors.Results: One week postoperatively, the ablated zone was larger than the original tumor in 178 of 181 lesions, which suggests ablation of the tumor and a margin of normal liver tissue. A progressive decline in lesion size was seen in 156 (88%) of 178 lesions, followed for at least 3 months (mean, 13.9 months; range, 4.9–37.8 months), which suggests resorption of the ablated tissue. Fourteen definite local treatment failures were apparent by increase in size and change in computed tomographic scan appearance, and eight lesions were scored as failures because of multifocal recurrence that encroached on ablated foci (22 total recurrences). Predictors of failure include lack of increased lesion size at 1 week (2 of 3 such lesions failed), adenocarcinoma or sarcoma (18 of 22 failures; P < .05), larger tumors (failures, M < 18cm³ vs. successes, M < 7cm³; P < .005) and vascular invasion on laparoscopic ultrasonography. By size criteria, 17 of 22 failures were apparent by 6 months. Energy delivered per gram of tissue was not significantly different (P < .45).Conclusions: LRFA has a 12% local failure rate, with larger adenocarcinomas and sarcomas at greatest risk. Failures occur early in follow-up, with most occurring by 6 months. LRFA seems to be a safe and effective treatment technique for patients with primary and metastatic liver malignancies.Presented at the 52nd Annual Meeting of the Society of Surgical Oncology, Orlando, Florida, March 4–7, 1999     

A randomized clinical trial of beta carotene vs placebo for the treatment of cervical HPV infection

The objective of the study was to determine if oral beta carotene would improve abnormalities observed in Papanicolaou smears or reduce the amount of HPV DNA in genital samples. A randomized double blind placebo controlled trial was designed for 117 women with abnormal cervical morphology, not undergoing laser ablative therapy, at The Royal Women's Hospital, Victoria. Thirty milligrams of oral beta carotene were administered daily for 12 months. Post-intervention cervical cytology and the amount of HPV DNA present on tampon specimens as determined by polymerase chain reaction and Hybrid Capture were the main outcome measures. After 12 months therapy there was no difference between the beta carotene and placebo groups in Papanicolaou smear results (58% and 62% normal) and HPV positivity (42% and 46% positive) ( P > 0.86). Women taking beta carotene were not more likely to have improved cervical cytology or a decrease in the amount of HPV DNA ( P > 0.2). The median post-intervention beta carotene level was 0.63 µm ml⁻¹ (range 0.04–1.6) for the beta carotene group and 0.15 µm ml⁻¹ (range 0.02–1.51) for the lecithin group ( P < 0.0001). This clinical trial did not identify a beneficial effect of 30 mg of oral beta carotene on cervical cytology, or on the amount of HPV DNA present from tampon specimens.     

Perinatal Infection with listeria Monocytogenes

Summary: Listeria monocytogenes has been increasingly recognized as a cause of intrauterine sepsis with associated perinatal wastage. The condition is mostly acquired through dietary intake and appropriate advice should be given to all pregnant women. The most common presentations in pregnancy include premature labour, an influenza-like illness and reduced fetal movements.
In this report, we present a series of 24 cases of perinatal listeria infection presenting to either our obstetric or neonatal units and confirmed by the microbiology department of the hospital. In particular, we wish to highlight 3 cases in which antenatal diagnosis and aggressive therapy was associated with a successful outcome. Amongst the remaining 21 cases in which an antenatal diagnosis was not made, there were 5 perinatal deaths and 1 mid-trimester loss at 18 weeks.
Clinicians must maintain a high index of suspicion for listeria, particularly in gravid patients who present with fever in the setting of a persistent 'flu-like' illness and premature labour. Once suspected, appropriate specimens for listeria culture should include blood, cervical swabs and midstream urine. Empirical antibiotic therapy with amoxicillin should be instituted while waiting for culture results in patients with possible Listeria monocytogenes sepsis.     

Calcium phosphate-containing precipitate and the carcinogenicity of sodium salts in rats

Sodium saccharin, ascorbate and other sodium salts fed at high doses to rats produce urinary bladder urothelial cytotoxicity with consequent regenerative hyperplasia. For sodium salts that have been tested, tumor activity is enhanced when administered either alone or after a brief exposure to a known genotoxic bladder carcinogen. These sodium salts alter urinary composition of rats resulting in formation of an amorphous precipitate. We examined the precipitate to ascertain its composition and further delineate the basis for its formation in rat urine. Using scanning electron microscopy with attached X-ray energy dispersive spectroscopy, the principal elements present were calcium, phosphorus, minor amounts of silicon and sulfur. Smaller elements are not detectable by this method. Infrared analyses demonstrated that calcium phosphate was in the tribasic form and silicon was most likely in the form of silica. Small amounts of saccharin were present in the precipitate from rats fed sodium saccharin (<5%), but ascorbate was not detectable in the precipitate from rats fed similar doses of sodium ascorbate. Large amounts of urea and mucopolysaccharide, apparently chondroitin sulfate, were detected in the precipitate by infrared analysis. Chemical analyses confirmed the presence of large amounts of calcium phosphate with variably small amounts of magnesium, possibly present as magnesium ammonium phosphate crystals, present in urine even in controls. Small amounts of protein, including albumin and alpha(2u)-globulin, were also detected (<5% of the precipitate). Calcium phosphate is an essential ingredient of the medium for tissue culture of epithelial cells, but when present at high concentrations (>5 mM) it precipitates and becomes cytotoxic. The nature of the precipitate reflects the unique composition of rat urine and helps to explain the basis for the species specificity of the cytotoxic and proliferative effects of high doses of these sodium salts.     

Influence of contractile agonists on the mechanism of endothelium-dependent relaxation in rat isolated mesenteric artery.

This study demonstrates directly that the relative contribution of nitric oxide (NO) and an NO synthase-independent repolarization to acetylcholine-evoked relaxation in rat isolated mesenteric resistance arteries is determined by the processes which mediate pre-contraction. Noradrenaline-induced contractions were reversed by acetylcholine via both NO and NO synthase-independent smooth muscle repolarization. In contrast, reversal of contractions to the thromboxane-mimetic, U46619, by acetylcholine was entirely mediated by the actions of NO, independently of a change in membrane potential.