Biomedical subjects
Publications and source records attributed to R Webber.
Following the accession of Poland to the European Union in 2004, large numbers of Polish migrant workers have come to the UK. We describe how this migration has impacted on an emergency department in the West Midlands, and suggest advice that should be given to such visitors about how to use the NHS.
OBJECTIVE: To determine whether motivational interviewing--a behavioural therapy for addictions-provided at home by specially trained midwives helps pregnant smokers to quit. DESIGN: Randomised controlled non-blinded trial analysed by intention to treat. SETTING: Clinics attached to two maternity hospitals in Glasgow. PARTICIPANTS: 762/1684 pregnant women who were regular smokers at antenatal booking: 351 in intervention group and 411 in control group. INTERVENTIONS: All women received standard health promotion information. Women in the intervention group were offered motivational interviewing at home. All interviews were recorded. MAIN OUTCOME MEASURES: Self reported smoking cessation verified by plasma or salivary cotinine concentration. RESULTS: 17/351 (4.8%) women in the intervention group stopped smoking (according to self report and serum cotinine concentration < 13.7 ng/ml) compared with 19/411(4.6%) in the control group. Fifteen (4.2%) women in the intervention group cut down (self report and cotinine concentration less than half that at booking) compared with 26 (6.3%) in the control group. Fewer women in the intervention group reported smoking more (18 (5.1%) v 44 (10.7%); relative risk 0.48, 95% confidence interval 0.28 to 0.81). Birth weight did not differ significantly (mean 3078 g v 3048 g). CONCLUSION: Good quality motivational interviewing did not significantly increase smoking cessation among pregnant women.
How can pregnant women be helped to stop smoking? This was a pilot study of midwife home-based motivational interviewing. Clients were 100 consecutive self-reported smokers booking at clinics in Glasgow from March to May 1997. Smoking guidance is routinely given at booking. In addition, intervention clients received a median of four home-based motivational interviewing sessions from one specially trained midwife. All sessions (n = 171) were audio-taped and interviews (n = 49) from 13 randomly selected clients were transcribed for content analysis. Three 'experts' assessed intervention quality using a recognized rating scale. Cotinine measurement on routine blood samples confirmed self-reported smoking change from late pregnancy telephone interview. Postnatal telephone questionnaire measured client satisfaction. Focus groups of routine midwives explored acceptability, problems and disruption of normal care. Fisher exact, chi 2 and Mann-Whitney tests compared enrolment characteristics. Two-sample t-tests assessed outcome between groups. Motivational interviewing was satisfactory in more than 75% of transcribed interviews. In this pilot study, self-reported smoking at booking (100 of 100 available) corroborated by cotinine (93 of 100) compared with late pregnancy self-reports (intervention 47 of 48; control 49 of 49) and cotinine (intervention 46 of 48; control 47 of 49) showed no significant difference between groups. Tools have been developed to answer the question: 'Can proactive opportunistic home-based motivational interviewing help pregnant smokers reduce their habit?'.
A simple health promotion message administered by village midwives raised bednet usage to over 60% in trial hamlets in north Shan State, Myanmar. Treatment of the nets in the study villages produced a reduction in malaria cases. Most villagers were prepared to buy their nets at market prices and were willing to pay for the cost of re-treatment of nets, but very poor, members of the Wa ethnic group required a half-price subsidy for them to afford them. The use of insecticide treated bednets was felt to be appropriate for undeveloped and remote areas of the country where malaria control was difficult.
Dopamine D2 receptors both acutely and chronically inhibit high-voltage-activated Ca2+ channels (HVA-CCs). Two alternatively spliced isoforms, D2L (long) and D2S (short), are expressed at high levels in rat pituitary intermediate lobe melanotropes but are lacking in anterior lobe corticotropes. We stably transfected D2L and D2S into corticotrope-derived AtT20 cells. Both isoforms coupled to inhibition of Q-type calcium channels through pertussis toxin-sensitive G proteins. Thus, we have created a model system in which to study the kinetics of D2-receptor regulation of Ca2+ channels. Rapid inhibition of HVA-CCs was characterized using a novel fluorescence video imaging technique for the measurement of millisecond kinetic events. We measured the time elapsed (lag time) between the arrival of depolarizing isotonic 66 mM K+, sensed by fluorescence from included carboxy-X-rhodamine (CXR), and the beginning of increased intracellular Ca2+ levels (sensed by changes in indo 1 fluorescence ratio). The lag time averaged 350-550 ms, with no significant differences among cell types. Addition of the D2-agonist quinpirole (250 microM) to the K+/CXR solution significantly increased the lag times for D2-expressing cells but did not alter the lag time for AtT20 controls. The increased lag times for D2L- and D2S-transfected cells suggest that at least a fraction of the Ca2+ channels was inhibited within the initial 350-550 ms. As this inhibition time is too fast for a multistep second messenger pathway, we conclude that inhibition occurs via a membrane-delimited diffusion mechanism.
The expression of the inducible isoform of nitric oxide synthase (NOS2, iNOS) is increased in patients undergoing sepsis as well as in animal models in which septic shock is induced by injection of bacterial lipopolysaccharide (LPS). Transforming growth factor-beta1 (TGF-beta1) potently suppresses NO production both in vitro and in vivo. After intraperitoneal injection of LPS, mice over-expressing a cDNA coding for active TGF-beta1 in the liver (Alb/ TGF-beta1) exhibited reduced serum levels of the NO reaction products NO2(-) + NO3(-) compared with controls. Paradoxically, while endotoxemic Alb/ TGF-beta1 mice expressed much less NOS2 protein in peritoneal exudate cells than did endotoxemic wild-type mice, Alb/TGF-beta1 mice expressed more NOS2 mRNA and protein in both liver and kidney. Alb/ TGF-beta1 mice treated with LPS had eightfold higher serum tumor necrosis factor alpha (TNF-alpha) levels and experienced increased mortality compared with wild-type mice, which was associated with renal insufficiency. These results suggest that renal dysfunction, decreased production of NO, and/or increased production of TNF-alpha are associated with increased mortality of endotoxemic Alb/TGF-beta1 mice.
PURPOSE: Ictal single-photon-emission computed tomography (SPECT) provides lateralization but has technical limitations: (a) a "truly ictal" injection must be shortly after seizure onset; (b) therefore, a seizure of brief duration may be missed; (c) more than one patient may need testing at any given time; (d) a trained health professional must stay next to each patient to inject; and (e) because the radionuclide is placed in the syringe in advance of the injection, decay of the radioactive element could result in less than optimal uptake, if the same volume of material were to be used regardless of the time after ligand preparation. METHODS: We developed an automated method of ligand injection that shortens time and increases efficiency of ictal SPECT ligand injection. By using an experimental setup, we compared manual injection times with times using an automated injection system. We determined relative costs and efficiency in work hours for the manual and automated methods. RESULTS: Injection times were 8-14 s with automated versus 19-26 s with manual injection. Readjusting volume for "ligand" decay was simple and accurate with the automated system. Injection times for clinical SPECT studies in three patients were 13, 13, and 12 s, respectively. The price of one pump equals 120 work hours of a nurse or 24 ictal injection attempts. Much of the nurse's time is "wasted" because no seizure occurs. CONCLUSIONS: The method can be more efficient of staff, shorten injection time, and facilitate obtaining "truly ictal" injections. It allows more cost-effective use of personnel.
This study tests the hypothesis that estimates of changes in bone mass derived from subtraction data obtained in accord with published methods are independent of the spatial aspect of the lesion being evaluated when calibrations are performed independently. Nineteen sliver-shaped bone chips ranging in mass from approximately 1 to 35 mg were orientated with broad side parallel to the facial surface of a hemisectioned dry human mandible and radiographed using conventional exposure parameters on conventional E-speed dental X-ray film. Also attached to the film was a standardized aluminium calibration wedge that facilitated quantitative analysis of resulting subtraction data using established methodology. The effects of scatter were simulated by the addition of a 1-cm-thick slab of tissue-equivalent plastic. A second series of exposures then was produced using the same respective spatial chip locations and projection geometries but each chip was reorientated such that its broad side was now positioned perpendicular to the mandibular facial surface. Finally, a comparable series of control exposures was produced without any chips or calibration wedge to facilitate subtraction. When paired bone estimates derived from the two chip orientations were compared (paired comparisons) using Student's t-test, a statistically significant difference (p < 0.05) was observed. These results also were tested for statistical significance using the non-parametric Wilcoxon test. As with the parametric analysis, the discrepancy between the parallel and perpendicular mass estimates was found to statistically significant (p < 0.05). The methods employed in this investigation thus resulted in bone mass estimates that varied significantly depending upon lesion orientation.
Lipid accumulation within macrophages is a major sequelae of atherosclerosis. Much of this lipid accumulation occurs within large, swollen lysosomes. We analyzed lipid accumulation in cultured macrophages using oxidized or acetylated low density lipoprotein (LDL) as the loading agent. Pigeon macrophages incubated for 48 h with mildly oxidized pigeon LDL (TBARS = 5-10 nmol/mg protein) showed significant increases in cellular cholesterol compared with untreated controls. Forty-eight percent of the increased cholesterol occurred as unesterified cholesterol. Treated cells had lipid-swollen lysosomes similar to those of atherosclerotic foam cells. The increase in lysosomal lipid was accompanied (correlation coefficient of 0.96) by increases in acid phosphatase staining cisternae of the Golgi and trans-Golgi network (TGN). THP-1 macrophages incubated with oxidized LDL showed similar lysosomal loading and Golgi/TGN hypertrophy. In contrast, macrophages incubated with acetylated LDL accumulated significant amounts of cholesterol but the increase occurred as cholesteryl ester (81% in pigeons) within cytoplasmic droplets and there was no associated increase in acid phosphatase-containing cisternae of Golgi or TGN. The correlation in both pigeon and THP-1 macrophages of oxidized LDL-induced lysosomal lipid accumulation and Golgi hypertrophy suggests a linkage of these two phenomena. This implicates intracellular membrane trafficking as a possible defect in foam cells of the atherosclerotic lesion.
Transmission of forest-related malaria was observed entomologically and epidemiologically for 2 transmission seasons in 1990 and 1991 in 5 villages of Mae Sariang district, Mae Hong Son Province, north-west Thailand. The entomological study included collections of mosquitos and determination of infection rate by using enzyme-linked immunosorbent assay in the residential villages and the farm huts. The epidemiological study included fortnightly visits to 30% of the households to interview and record movement activities and illness of villagers. Circumsporozoite proteins, in most cases of Plasmodium falciparum, were detected in Anopheles minimus species A, An. dirus s.l., An. maculatus s.s. and An. sawadwongporni in residential villages and/or farm huts, suggesting transmission could occur there. Movement of people away from their residences occurred throughout the year for several reasons with a sharp peak in July for agricultural activity, mainly ploughing and planting for rice cultivation. The relative risk of infection for people engaged in agricultural activity was 3 times that of people living in the residential villages. Although a higher biting density of vectors was generally evident at the farm huts, the estimated inoculation rates in the 2 settings were similar. Movement for forest activity increased after harvesting rice in the cool dry season and carried the highest malaria risk, suggesting different epidemiological and probably entomological conditions which need further investigation. The significance is discussed of discrepancies between the case classification system used by this study and that used by malaria sector staff.
In Alzheimer's disease (AD), affected neurons accumulate beta amyloid protein, components of which can induce mouse microglia to express the high-output isoform of nitric oxide synthase (NOS2) in vitro. Products of NOS2 can be neurotoxic. In mice, NOS2 is normally suppressed by transforming growth factor beta 1 (TGF-beta 1). Expression of TGF-beta 1 is decreased in brains from AD patients, a situation that might be permissive for accumulation of NOS2. Accordingly, we investigated the expression of NOS2 in patients with AD, using three monospecific antibodies: a previously described polyclonal and two new monoclonal antibodies. Neurofibrillary tangle-bearing neurons and neuropil threads contained NOS2 in brains from each of 11 AD patients ranging in age from 47 to 81 years. NOS2 was undetectable in brains from 6 control subjects aged 23-72 years, but was expressed in small amounts in 3 control subjects aged 77-87 years. Thus, human neurons can express NOS2 in vivo. The high-output pathway of NO production may contribute to pathogenesis in AD.
Several members of the matrix metalloproteinase family have been reported to cleave aggrecan in the interglobular domain between Asn-341 and Phe-342. An antiserum was prepared against a peptide conjugate corresponding to the C-terminal sequence of the matrix metalloproteinase-generated aggrecan G1 fragment (Phe335-Val-Asp-Ile-Pro-Glu-Asn341). A quantitative radioimmunoassay, with a limit of detection of about 80 pM, was developed using this antiserum. This antiserum requires the free carboxyl group of the C-terminal asparagine for optimal recognition. If the C-terminal asparagine is excised from the sequence, replaced with closely related amino acids, or extended across the matrix metalloproteinase cleavage site, there is a 40-10,000-fold loss in detection. Using peptides cleaved from the N-terminus, it was determined that the antiserum requires the entire Phe-Val-Asp-Ile-Pro-Glu-Asn sequence for optimal recognition. The radioimmunoassay detects matrix metalloproteinase-generated G1 fragments with similar sensitivity to the Phe-Val-Asp-Ile-Pro-Glu-Asn peptide, but it does not recognize intact aggrecan. Immunoreactive aggrecan G1 fragments of molecular mass 50 kDa are generated by the matrix metalloproteinases stromelysin and gelatinase A. In contrast, under identical conditions, the closely related metalloproteinases, gelatinase B and collagenase, as well as cathepsin G, cathepsin B and human leucocyte elastase, did not generate a G1 fragment recognized by the antiserum. The anti-Phe-Val-Asp-Ile-Pro-Glu-Asn serum detects stromelysin-generated aggrecan G1 fragments from mouse, guinea pig, rabbit and human, indicating that the detection is not species-specific. This antiserum and radio-immunoassay should be useful for quantifying and characterizing matrix metalloproteinase-generated aggrecan G1 fragments in articular cartilage and synovial fluids from humans and various animal models of articular-cartilage destruction.
The peptidergic innervation of parenchymal and vascular components in the human parotid gland was investigated by double-labelling fluorescence. Peptide immunoreactivity in nerve fibres was correlated with the presence of tyrosine hydroxylase (TH). By light microscopy, acinar innervation consisted of fibres with the combinations neuropeptide Y (NPY)/TH and NPY/vasoactive intestinal polypeptide (VIP). Some fibres were solely NPY, TH or VIP immunoreactive. Rarely, substance P (SP)/calcitonin gene-related (CGRP)-immunolabelled fibres were associated with acini. Intercalated ducts were often approached by NPY/TH- and VIP-containing fibres. VIP innervation of excretory ducts was sparse. Intralobular and intralobar excretory ducts, in addition to NPY and TH, revealed CGRP and CGRP/SP innervation, whereas nerve fibres on interlobar excretory ducts very rarely contained NPY and none of the other mediators. Vascular innervation consisted of NPY/TH and SP/CGRP fibres; in a few fibres SP was colocalized with leu-enkephalin. Large arteries were encircled by some VIP-positive fibres. The findings suggest a specific participation of neuropeptides and of peptide combinations in the regulation of parotid exocrine function.
The existence of the mu rhythm and its general anatomical and physiological relationships are well known. There are few data, however, regarding the details of its anatomical and physiological specificity. We implanted fronto-temporal subdural electrode grids in 9 patients with intractable epilepsy to facilitate their surgical management. A 7-11 Hz cortical mu rhythm was observed in 5-16 electrodes located over the sensorimotor cortex as mapped by electrical stimulation. The mu rhythm was blocked by contralateral face and arm movements, passive movements of contralateral arm, and by ipsilateral arm movements. There was correspondence between the body area movement of which blocked the mu at a given site and the body region that was affected by stimulation at the same site. Power spectral analysis showed an overall decrease in power in all frequency bands. This was less prominent in the 14-100 Hz band resulting in a relative increase in high frequency power in association with movement. We conclude that both the presence and blocking of mu rhythm are specific to the somatic representation of the cortex from which it is recorded. Its functional significance may be similar to other sensory rhythms like the occipital alpha rhythm.
Thrombin-antithrombin III complex (TAT) concentration was measured in 27 control and 155 intensive care patients to (a) establish normal reference ranges, (b) measure thrombin generation in critically ill patients, and (c) determine the characteristics of the TAT assay for the diagnosis of disseminated intravascular coagulation (DIC) in children. The normal reference range was 1-4.3 micrograms/l (median 2.3 micrograms/l), and 89.7% of patients had raised TAT concentrations. Median TAT concentrations in the presence of DIC (27 micrograms/l) were significantly higher than in its absence (8 micrograms/l). Sensitivity, specificity, and positive and negative predictive values of the assay were 97.3%, 28.3%, 76.3%, and 81.3%, respectively, at a cut off of 4 micrograms/l. Excess thrombin production occurs in the majority of critically ill children. The TAT assay is potentially useful in the diagnosis of DIC in children.
Tyrosine hydroxylase (TH)- and peptide-immunoreactivity of postganglionic neurons and of nerve fibres in guinea pig lumbar paravertebral sympathetic ganglia 2-4 after transection of the communicating rami and the visceral branches, respectively, were investigated by single- and double-labelling techniques. Six subpopulations of postganglionic neurons were discriminated immunohistochemically: two cell types, which were immunoreactive to only one of the applied antisera - TH, and vasoactive intestinal polypeptide (VIP); and four cell types in which immunoreactivity was colocalized - TH/neuropeptide Y (NPY), NPY/VIP, dynorphin/alpha-neoendorphin and dynorphin (alpha-neoendorphin)/NPY. Small intensely fluorescent (SIF) cells dependent on their location exhibited differential immunobehaviour to NPY-/dynorphin-(alpha-neoendorphin-) and TH-antisera. Immunoreactivity to substance P (SP), calcitonin gene-related peptide (CGRP), met-enkephalin-arg-phe (MEAP) and leu-enkephalin was present in nerve fibres but not in postganglionic neurons with frequent colocalization of SP/CGRP- and MEAP/leu-enkephalin- and, sometimes leu-enkephalin/SP- and dynorphin/SP-immunoreactivity. TH-immunoreactive intraganglionic nerve fibres were numerically more increased after cutting the visceral branches, than after transection of the communicating rami. Vice versa, NPY-, VIP-, dynorphin- and alpha-neoendorphin-immunoreactive nerve fibres were particularly increased in number after cutting the communicating rami. Many but not all of the nerve fibres exhibited colocalization of two of these peptides. SP-, CGRP-, and enkephalin-immunoreactive nerve fibres were not visibly affected by cutting the visceral branches but virtually disappeared after lesioning the communicating rami.
Safe parameters for electrical cortical stimulation in humans are difficult to estimate from the animal experimental literature. We therefore examined the light microscopic histology at a total of 11 sites of direct subdural electrical stimulation, taken as part of anterior temporal lobectomies in 3 patients. Stimulations had been done through 3.175 mm diameter electrodes, with 0.3 msec square wave pulses of alternating polarity at 50 pulses/sec. In 2 patients, one site each had been used as a common reference for stimulation, receiving over 251 stimulation trials, most of 2-5 sec duration, at currents of 12.5-15.0 mA, 1 day prior to resection. The maximum charge per phase was 4.0-4.4 microC; the maximum charge density was 52-57 microC per geometric cm2 per pulse at the electrode surfaces. Comparison of hematoxylin and eosin, periodic acid-Schiff, and cresyl violet-stained material from the electrode sites with that from other regions did not show any histologic abnormalities attributable to the electrical stimulation. The relatively brief and intermittent periods utilized for human stimulation testing do not appear to cause structural damage at the light microscopic level at charge densities that exceed the threshold for damage established in animal studies with more continuous, chronic stimulation schedules.
delta-Aminolaevulinic acid (ALA) was determined by g.l.c. with electron-capture detection. Normal plasma level was 92 nmol/l (SD = 39, n = 89, range 24-270 nmol/l). ALA was undetectable in 35 of 53 samples of normal cerebrospinal fluid (limit of assay 2 nmol/l). The mean of the other 18 samples was 19 nmol/l (SD = 10, range 6-36 nmol/l). Salivary ALA was generally only 10-30% of the plasma level in normal and porphyric subjects. Erythrocytes of normal and porphyric subjects contained no detectable ALA and were impermeable to its entry. ALA clearance correlated closely with that of creatinine, consistent with it being excreted by glomerular filtration with limited tubular reabsorption. In chronic renal failure, serum ALA was elevated to a maximum of three to four times the normal, but its urinary excretion was reduced, in keeping with lessened production. In two cases of acute intermittent porphyria with overwhelming neuropathy the maximum plasma levels of ALA were 9 and 12 mumol/l. Haematin infusion decreased the ALA levels but without obvious clinical benefit. Limited neurological recovery occurred without major reduction in plasma levels of ALA. One subject's attack was precipitated by pregnancy. The neonate was apparently normal, despite high levels of ALA in maternal plasma throughout gestation and a high level of ALA in the cord blood. The observations described here do not support the view that ALA may be directly neurotoxic.