Assessment of the stability of human viruses and coliphage in groundwater by PCR and infectivity methods.

AIM: To investigate the potential health hazard from infectious viruses where coliphages, or viruses by polymerase chain reaction (PCR), have been detected in groundwater. Two aspects were investigated: the relationship between infectivity and detection by PCR and the stability of coliphage compared to human viruses. METHODS AND RESULTS: Virus decay (1 year) and detection (2 years) studies were undertaken on groundwater at 12 degrees C. The order of virus stability from most to least stable in groundwater, based on first-order inactivation, was: coliphage PhiX174 (0.5 d(-1)) > adenovirus 2 > coliphage PRD1 > poliovirus 3 > coxsackie virus B1 (0.13 d(-1)). The order for PCR results was: norovirus genotype II > adenovirus > norovirus genotype I > enterovirus. CONCLUSIONS: Enterovirus and adenovirus detection by PCR and the duration of infectivity in groundwater followed similar trends over the time period studied. Adenovirus might be a better method for assessing groundwater contamination than using enterovirus; norovirus detection would provide information on a significant human health hazard. Bacteriophage is a good alternative indicator. SIGNIFICANCE AND IMPACT OF THE STUDY: PCR is a useful tool for identifying the health hazard from faecal contamination in groundwater where conditions are conducive to the survival of viruses and their nucleic acid.

Quantitative RT-PCR for the enumeration of noroviruses (Norwalk-like viruses) in water and sewage.

AIMS: Aims of investigation: (i) develop a quantitative RT-PCR for noroviruses and (ii) evaluate it on environmental samples. METHODS AND RESULTS: Noroviruses in environmental water samples were concentrated by adsorption/elution/flocculation. Sewage was processed by clarification and protein flocculation. Norovirus-specific cDNA produced by primer-directed reverse transcription of extracted RNA was amplified by LightCycler and accumulation of product monitored by observation of fluorescence induced by the incorporation of SYBR Green. Absolute quantitation of product was achieved by construction of standard curves using quantitative standards produced by cloning a modified sequence of the 3'-region of the forward norovirus primer. Reaction specificity was confirmed by analysis of product melting curves. CONCLUSIONS: Sewage was found to contain up to 1.8 x 10(6) norovirus cDNA copies per 100 ml and effluent contained up to 1.7 x 10(6) copies per 10 l. Marine bathing water and recreational river waters also contained noroviruses. Sample inhibition was detected to varying degrees in most sample types. SIGNIFICANCE AND IMPACT OF THE STUDY: The study will enable quantitative comparisons be made of samples from different locations and treatment processes, and inform the debate on the revision of the EU Bathing Water Directive; it will have important implications for the analysis of samples derived from different aquatic matrices, and from foods.

Minimally invasive surgery for osteoid osteoma of the proximal femur.

Seven patients with osteoid osteoma of the proximal femur were treated by percutaneous excision of the nidus. The combination of preoperative localisation by tomography and intraoperative localisation by image intensifier resulted in a curative procedure with minimal bone resection in all cases, although a second operation was required in one patient.

A computerised system of screening for deep venous thrombosis.

We have developed a computer controlled system of strain gauge plethysmography for use as a screening tool for proximal segment venous thrombi which is simple to use, well tolerated by patients and extremely accurate. The computerised test was evaluated in 171 limbs of 163 symptomatic patients by comparison with subsequent ascending venography. Each of twenty occlusive proximal segment thrombi were identified, one non occlusive thrombus screened normal giving an overall sensitivity of 95.2%. The specificity of the test was 80% with a negative predictive value of 99.0%. The computerised system allows accurate screening for proximal segment venous thrombosis, and may permit more selective use of venography in the symptomatic post-operative limb.

Orthopaedic surgeons and thromboprophylaxis.

OBJECTIVE: To assess attitudes to the use of thromboprophylaxis among orthopaedic surgeons in the United Kingdom. DESIGN AND SUBJECTS: Single page postal questionnaire to all 926 active orthopaedic surgeons who are members of the British Orthopaedic Association. RESULTS: The response rate was 70% (659 surgeons), of whom 595 (90%) used some form of prophylaxis. Most (548; 83%) used drugs but 47 (7%) used only elasticated stockings. A history of thromboembolic disease, hip surgery, and obesity was seen as the main risk factor. Ineffectiveness was the principal reason for not using prophylaxis. CONCLUSIONS: Most orthopaedic surgeons use regimens of thromboprophylaxis, though many of these are of limited value. Improvements in the efficacy and safety of prophylactic agents, combined with ease of administration, would increase the use of such agents and make orthopaedic surgery safer for the patient.

Management of blunt injuries of the axillary artery and the neck of the humerus: case report.

Axillary artery injury, a rare vascular complication of fracture of the humeral neck, is rendered unique by the concomitant subluxation of the humeral head. A coordinated vascular and orthopaedic surgical approach is necessary to reconstruct both the shoulder joint and the artery. The operative techniques chosen may determine long-term outcome.

Evaluation of the biochemical effects of CHIP in normal and tumour-bearing C3H mice.

The biochemical effects of CHIP have been studied in C3H mice with and without transplanted mammary tumour. The maximum tolerated dose of CHIP was first determined by lethality and intestinal crypt assays to be 40 mg kg-1 and this dose was used to assay the time course of gastric distension and the pattern of drug distribution. A high level of CHIP uptake was found in liver as well as kidney. For this reason, tests for both kidney and liver damage were undertaken up to 60 days post-treatment using a dose of 10 mg kg-1 Neoplatin for comparison. Despite the high level of platinum drug uptake in liver, there was no biochemical evidence of hepatocellular or cholestatic damage. From the renal point of view, there was the expected rise in serum urea after Neoplatin but not after CHIP and there was also a rise in urinary NAG after Neoplatin in tumour bearing mice. There was, however, evidence of suppression of protein levels including enzymes, following treatment with both drugs. Tumour-bearing mice respond differently from normal mice following treatment with platinum drugs. The study confirms that CHIP is less toxic than Neoplatin.

The effect of C3H mouse mammary tumour on the levels of serum and urine analytes in vivo.

A study of C3H mice implanted with mammary tumours has shown that the levels of serum total protein, alanine transaminase and alkaline phosphatase are all lower than those found in normal mice, while aspartate transaminase is higher. Serum urea values were similar to normal levels, but creatinine was lower in males and higher in females. In the male mice, urine protein and urine N-acetyl-beta-D-glucosaminidase (NAG) activity were lower than in normal mice. Comparisons were made with age and sex matched controls which was found to be important for alkaline phosphatase, as this was shown to decrease with increasing age of the mice over the period from 10-30 weeks of age. The analyte values found in this study provide useful base-line data for assessing biochemical toxicity of cancer chemotherapy agents. It has been shown that some of these values can vary with age, or can be different if tumour-bearing mice are used instead of normal mice.

The radiomimetic properties of a platinum drug.

CHIP (cis-dichlorobis isopropylamine trans-dihydroxy platinum IV) is a second-generation platinum co-ordination complex which potentiates the effects of radiation. Comparisons of the biological effects of CHIP and X rays upon Chinese hamster (ovary) cells have shown similarities with respect to the shape of the dose-response curves, clone size distributions and perturbation of the cell cycle. Unlike irradiated cells however, CHIP-treated cells showed no recovery from sublethal damage and no variation in sensitivity throughout the cell cycle. CHIP is a radiomimetic drug in some respects but not in others.

Sister chromatid exchanges induced by two radiosensitizing platinum compounds (cis-dichloro-bis isopropylamine trans dihydroxy platinum IV (CHIP) and cis platinum metronidazole2Cl2(FLAP)) in CHO cells in vitro.

Sister chromatid exchange (SCE) induction by two radiosensitizing platinum compounds (cis-dichloro-bis isopropylamine trans dihydroxy platinum IV (CHIP) and cis-platinum metronidazole2 Cl2 (FLAP] was studied in CHO cells in vitro. Both drugs induced SCE in a dose dependent manner. CHIP was a much more potent inducer of SCE than FLAP and produced almost 4 times as many SCE as FLAP at equimolar concentrations and twice as many at equitoxic dosage. Induction of SCE by a component of the FLAP molecule--metronidazole--was also examined. It did not cause any increase of SCE frequency over the control level when applied at 10 times the highest concentration of FLAP which was used.

The mode of action of cis dichloro-bis (isopropylamine) trans dihydroxy platinum IV (CHIP) studied by the analysis of chromosome aberration production.

The induction of chromosome damage by the Platinum complex CHIP in Chinese hamster ovary (CHO) cells has been studied, together with the relationship between cell survival and aberration frequency. The type and frequency of chromosome aberrations observed in asynchronous and G1 phase treated cells indicated a similar mode of action to that of bifunctional alkylating agents. A log-linear relationship was observed between the frequency of chromatid aberrations (excluding gaps) and the level of survival after CHIP treatment, with approximately one aberration per cell corresponding to 37% survival.

Hypoxic cell sensitization to radiation damage by a new radiosensitizer: cis-dichloro-bis(1-(2-hydroxyethyl)-2-methyl-5-nitroimidazole-N3)platinum(II) (flap).

A new, stable platinum coordination complex (FLAP) containing the 5-nitroimidazole, metronidazole, has been prepared and characterized. The square-planar platinum(II) complex has two metronidazole molecules and two chlorine atoms in the cis configuration. The properties of FLAP differ significantly from metronidazole alone or other platinum complexes tested in the same system. It has a low toxicity towards Chinese hamster ovary cells and is a very effective radiosensitizer toward hypoxic cells in vitro: a one-h pretreatment with a non-toxic dose of 50 microM gave an enhancement ratio of 2.4. No potentiation of aerated cells to X-irradiation damage was observed after a similar schedule of pretreatment at the higher dose of 100 microM FLAP.