Biomedical subjects
Publications and source records attributed to A Warwick.
Acute leukaemia is encountered rarely in obstetric practice, occurring once in every 100,000 pregnancies. Such cases are usually diagnosed in the second and third trimesters. We describe a patient who developed a postpartum haemorrhage (PPH) as the presenting feature of acute promyelocytic leukaemia, which, to the best of our knowledge, has not been reported previously.
This paper examines the growth and uptake of phosphorus into algal biofilms in the River Kennet, a lowland chalk (Cretaceous-age) stream in southern England. Algal biofilms were grown on artificial plastic substrates (templates) placed (i) on the riverbed and (ii) within the mid-water column. Experiments were set up to examine differences in growth rates of newly colonising biofilms compared with biofilms left to accumulate for periods of up to 6 months. Rates of algal biofilm production were measured by the chlorophyll a concentration that had accumulated per cm2 over the number of days that the biofilm template had been immersed in the river water. An algal biofilm bloom occurred in early spring, prior to peak suspended chlorophyll a concentrations within the water column. Biofilm samples collected in February and March had the highest chlorophyll a and total phosphorus concentrations. The biofilm bloom corresponded with increased solar radiation and declining river flow conditions. Periodic increases in soluble reactive phosphorus concentrations in the overlying river water did not correspond with any significant increase in biofilm production. These results suggest that light, rather than phosphorus is a key factor for biofilm growth in the River Kennet. Higher rates of chlorophyll a development in mid-water column biofilms may be linked to greater light exposure; however, maximum total-P concentrations were similar for both bed and water column biofilms. Newly colonising biofilms exhibited higher chlorophyll a and total-P concentrations than biofilms left to accumulate over longer terms, suggesting that fresh substrate availability promotes high rates of biofilm growth. Both 'condensed and organic' P (stored in biomass) and 'inorganic' (mineral) P fractions within the biofilms were present in varying proportions, although the early spring biofilm bloom resulted in maximum proportions and absolute concentrations of 'condensed and organic' P. Calcite was the only crystalline mineral detected within the biofilms. Ratios of Ca:inorganic P are largely consistent with the presence of CaCO3-P co-precipitates, although one very low value suggested that there may also be additional sources of inorganic P, possibly P adsorbed to clays or organics within the biofilm. However, poor linkages between CaCO3 and inorganic P concentrations suggest that, although the inorganic P fraction within the biofilm may be derived largely from CaCO3-P co-precipitation, the subsequent processes controlling overall CaCO3 and inorganic P concentrations in the biofilm are complex.
OBJECTIVE: To evaluate whether routinely giving an antibiotic after loop diathermy excision of the cervical transformation zone reduced post-operative vaginal loss. DESIGN: Prospective, randomised, double-blind placebo controlled parallel study. PARTICIPANTS: Five hundred women undergoing loop diathermy excision in a colposcopy clinic. INTERVENTION: Administration of either ofloxacin 400 mg (2x200 mg) once daily for 5 days or an identical placebo. MAIN OUTCOME MEASURE: Vaginal loss, assessed using a pictorial chart. RESULTS: No significant difference in post-operative vaginal loss was found. CONCLUSION: Routine antibiotic prophylaxis after loop diathermy excision is not justified.
RATIONALE AND OBJECTIVES: To measure the hepatic uptake and biliary elimination kinetics of gadolinium (Gd)-EOB-DTPA in dogs. METHOD: Two groups of four beagles each were anesthetized and given an intravenous bolus of 25 mumol/kg or 250 mumol/kg of Gd-EOB-DTPA. Blood, hepatic bile, and urine were collected over 140 minutes, and liver samples were obtained immediately after the dogs were killed. Conventional T1-weighted spin echo sequences of the liver were performed on a 1.5-Tesla (T) magnetic resonance imager during sampling. A ninth beagle received a bolus of 25 mumol/kg followed 140 minutes later with a bolus of 250 mumol/kg of Gd-EOB-DTPA. Wedge liver biopsies were obtained for Gd estimation at various times after dosing, and Gd concentration was measured by inductively coupled plasma atomic emission spectroscopy. RESULTS: The plasma concentration of Gd-EOB-DTPA decreased in a biexponential manner with half-lives of approximately 4 minutes and 60 minutes for the distribution and elimination phase independent of the dose given. Gadolinium bile concentration reached peak values between 80 and 140 minutes: 6.3 +/- 1.6 mmol/L for the low dose (LD) and 11.6 +/- mmol/L for the high dose (HD). Bile Gd output was 62.0 +/- 8.8 (LD) and 78.3 +/- 30.2 (HD) nmol/minute-kg 50 to 80 minutes after injection. Gadolinium-EOB-DTPA was excreted by the biliary route to 24.8 +/- 2.6 (LD) and 3.6 +/- 1.2 (HD) percent of the dose within 140 minutes. Liver Gd concentration was 0.43 +/- 0.14 (LD) and 4.3 +/- 0.5 (HD) mmol/kg liver tissue at the conclusion of the studies. Calculated concentrations in the hepatocyte were 60 (LD) and 15 (HD) times higher than in plasma at 25 minutes after dosing. Whereas the low dose exhibited excellent contrast enhancement for the whole period, the high dose displayed a biphasic signal enhancement with a decreasing signal caused by the too-high hepatic gadolinium accumulation. CONCLUSIONS: Transport of the Gd-EOB-DTPA into the hepatocyte exceeded elimination from hepatocyte to bile. The high dose defined a biliary transport maximum for Gd-EOB-DTPA of 78.3 +/- 30.2 nmol/minute-kg. The liver accumulation results from fast transport into the hepatocyte and rate-limited slower transport from hepatocyte to bile. The accumulation occurs against a strong concentration gradient, suggesting energy-dependent active transport into the hepatocyte.
The factors that determine progression of cervical intra-epithelial neoplasia (CIN) to squamous cell carcinoma (SCC) are unknown. Cigarette smoking is a risk factor, suggesting polymorphism at loci that encode carcinogen-metabolizing enzymes such as glutathione S-transferase (GSTT1, GSTM1) and cytochrome P450 (CYP2D6) may determine susceptibility to these cancers. We have studied the frequency of the null genotype at the theta class GSTT1 locus in women with low-grade CIN, high-grade CIN and SCC. The control group comprised women with normal cervical pathology suffering menorrhagia. We found the frequency of GSTT1 null in the control and case groups was not significantly different, though frequency distributions of combinations of the genotype with smoking in mutually exclusive groups in the high-grade CIN group and the other case groups were significantly different. Interactive effects of GSTT1 null with the GSTM1 null and CYP2D6 EM genotypes, and cigarette smoking were also studied by comparing the multinomial frequency distributions of these factors over mutually exclusive categories. These showed no significant differences between the controls and SCC or low-grade CIN. Frequency distributions in high-grade CIN, however, were significantly different to the controls, and both SCC and low-grade CIN; frequency distributions of GSTT1 null with smoking and CYP2D6 EM, individually and in combination, were significantly different. However, inspection of our data does not indicate that GSTT1 null is a major factor mediating risk. Thus, comparison of chi 2 values for the differences between frequency distributions in high-grade CIN and other groups shows that values for combinations of GSTT1 null with other factors are lower than those for equivalent combinations with smoking and CYP2D6 EM. Interestingly, the combination GSTT1 null/GSTM1 null did not appear to influence susceptibility to CIN or SCC.
The aim of our study was to compare the safety and efficacy of a new preparation, Dysprosium-165 Hydroxide Macroaggregate (165Dy) with Yttrium-90 Silicate (90Y) for radiation synovectomy of the knee in patients with RA and OA. A multicentre double blind clinical trial with subjects randomized to receive 165Dy or 90Y was undertaken in Sydney, Melbourne and Perth. Seventy knees of 59 patients were studied, using as clinical end point measurements, pain in the knee on walking, pain in the knee at rest and stiffness in the knee after rest. Cytogenetic damage, knee retention and extra-articular spread of the radionuclide to regional lymph nodes, liver, urine and blood were evaluated. There was no significant difference in clinical response in the two treatment groups for either RA or OA. Chromosomal changes occurred with equal frequency and the knee retention and extra-articular leakage of radiocolloids to regional lymph nodes and liver were comparable in the two groups. For radiation synovectomy of the knee, 165Dy is at least as safe and as effective as 90Y and has the advantage of a short half-life (2.334 h) and hence requires a shorter period of post-injection immobilization and hospitalization.
Explore the source record for details and available documents.
This complex study was designed to measure the transport and excretion characteristics of gadolinium ethoxybenzyl diethylenetriaminepentacetic acid (Gd-EOB-DTPA) in dog's livers following bolus and infusion. Simultaneous T1 magnetic resonance imaging was performed to measure maximum signal enhancement. Anaesthetized dogs had cannulation of the common bile duct and urinary bladder for collections and cannulation of the femoral artery and vein for monitoring, blood sampling and infusion. Gd-EOB-DTPA was administered by bolus (range 12.5-200 mumol/kg) and infusion (range 0.4-6.4 mumol/min per kg). An hepatic transport maximum 0.09-0.15 mumol/min/kg was achieved with a blood concentration of 0.03-0.06 mumol/mL. Marked hepatic affinity for Gd-EOB-DTPA was demonstrated with measurements of liver concentration. Maximum T1 signal enhancement was achieved with blood Gd-EOB-DTPA concentration of 0.02-0.03 mumol/mL and a liver concentration of 1-2 mumol/g. The transport maximum for Gd-EOB-DTPA in the dog was similar to that for ipodate and iodipamide and effective imaging was achieved with sub-maximal doses. The maximum signal enhancement at blood concentrations less than required for maximum transport suggest a wide latitude for effective clinical imaging.
OBJECTIVE: To compare assisted vaginal delivery by forceps with delivery by vacuum extractor, where a new vacuum extractor policy was employed which dictated the cup to be used in specific situations. DESIGN: Multicentre randomised controlled trial. SETTING: Four district general hospitals in the West Midlands. SUBJECTS: Six hundred-seven women requiring assisted vaginal delivery, of whom 296 were allocated to vacuum extractor delivery and 311 to forceps. MAIN OUTCOME MEASURES: Delivery success rate, maternal perineal and vaginal injuries, maternal anaesthetic requirements, neonatal scalp and facial injuries. RESULTS: Of the vacuum extractor group, 85% were delivered by the allocated instrument compared to 90% in the forceps group (odds ratio (OR) 0.64; 95% confidence intervals (CI) 0.4-1.04). However, more women in the vacuum extractor group were delivered vaginally (98%) than in the forceps group (96%). There were significantly fewer women with anal sphincter damage or upper vaginal extensions in the vacuum extractor group (11% vs 17%, OR 0.6; 95% CI, 0.38-0.97). There were significantly fewer women in the vacuum extractor group requiring epidural or spinal anaesthetics (25.4% vs 32.7%, OR 0.69; 95% CI 0.49-0.99) or general anaesthetics (1% vs 4%, OR 0.17; 95% CI 0.04-0.76). Although there were significantly more babies in the vacuum extractor group with cephalhaematomata (9% vs 3%, OR 3.3; 95% CI 1.4-7.4) there were fewer babies in the vacuum extractor group with other facial injuries. There were three babies in the forceps group with unexplained neonatal convulsions. CONCLUSIONS: Assisted vaginal delivery using the new vacuum extractor policy is associated with significantly less maternal trauma than with forceps. Further studies are required to assess neonatal morbidity adequately.
This study used a radionuclide imaging technique to map the spread and density contours of phenol in glycerin injected into the epidural space of cancer patients. Correlations were made between phenol injectate volume, sequence of injection, position of patient, and resultant epidural spread and analgesic outcome. Fifteen patients with cancer pain (average age of 61 years) were treated with serial epidural phenol in glycerin injections. Phenol in glycerin is miscible with [99mTc]sulfur colloid. An assumption was made that the admixture injected epidurally was inseparable prior to absorption and the spread was recorded by continuous gamma camera observations with computer collection for 30 min postinjection. The spread of injectate volumes of 2, 3, and 4 ml were compared and further correlations made between observed spread and sequence of injections (first to fifth in series within each patient) and position of patient. Small volumes of phenol may spread extensively in the epidural space (3 ml spreads a mean 13.6 segments) with wide variation among patients. Initial phenol injections spread further than subsequent injections. Maximum spread is achieved by 15 min postinjection and epidural distribution is mostly uniform, independent of patient position. Good analgesia was obtained in 14 patients (93%). Epidural neurolysis using serial injections of small volumes of phenol in glycerin is an effective, safe technique for cancer pain relief. Injectate volumes larger than 3 ml may be unnecessary and potentially dangerous.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Chrysosporium species caused an invasive infection in an 18-year-old patient following allogeneic sibling bone marrow transplant for T lineage acute lymphoblastic leukemia. This infection began as a facial swelling and extended into the central nervous system. Fungal disease spread rapidly despite antifungal agents. An autopsy showed fungal involvement of brain, lungs, liver and kidneys.
Explore the source record for details and available documents.
The optimal conditions for labelling infective larvae of Strongyloides ratti with 67gallium citrate were determined. Radiolabelled larvae were injected s.c. into normal and previously infected rats. The distribution of radioactivity in these animals was compared with that in rats infected subcutaneously with a similar dose of free 67Ga by using a gamma camera linked to a computer system. Whereas free 67Ga was distributed throughout the body and excreted via the hepatobiliary system, the bulk of radioactivity in rats injected with radiolabelled larvae remained at the injection sites. Direct microscopical examination of these sites, however, revealed only minimal numbers of worms. When rats were infected percutaneously with radiolabelled larvae, it was found that most radioactivity remained at the surface, despite penetration of worms. When infective larvae were exposed to CO2 in vitro and examined carefully by light microscopy, loss of an outer coat was observed. It was concluded that infective larvae lose an outer coat on skin penetration.
This paper describes a practical procedure to establish a sensitive radioimmunoassay for the measurement of human thyroglobulin (HTg) in serum. The assay enables a clear distinction to be made between levels of HTg indicating the presence or absence of functioning thyroid tissue. It compares the use of HTg serum levels with the conventional I-131 scintigram as a marker for recurrent thyroid cancer. In addition, a simple and sensitive radioimmunologic assay is described for the determination of serum antithyroglobulin autoantibodies, the presence of which may give falsely elevated HTg levels.
Adult or weanling C(3)H mice were found to be genetically resistant to a strain of mouse hepatitis virus. Infant C(3)H mice, however, developed infection and died from mouse hepatitis virus when minimal infectious doses of virus were given to them. There was a delay in the time of death compared to that of the genetically susceptible strain, and the virus recovered from these mice had increased pathogenicity for C(3)H mice. The ontogeny of resistance to hepatitis in the C(3)H mice thus progresses from delayed susceptibility to complete resistance as the age of the host increases. It is reflected in increased resistance of macrophages derived in vitro from liver cultures of infant mice of different ages. This increase in resistance with age was reduced by maintaining the cultures for a longer period of time before inoculation, or by increasing the number of explants in a given culture. Resistant cells were uniformly furnished by mice age 16 days, or more. It is concluded that a process of maturation of resistance of the cells takes place after the mice are born, but that this does not continue under in vitro conditions, and that it may be modified by the environment of the cells.
Explore the source record for details and available documents.