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Biomedical subjects

S Thomas

Publications and source records attributed to S Thomas.

At least 91 records · Page 5Linked to original sources
PubMed2003

Sorption of Cu and Zn by bone charcoal.

Bone charcoal is being developed as a treatment for decontaminating polluted water. In particular, its potential to adsorb metal species from contaminated water supplies is being examined. In this study, bone charcoal was used in batch and column experiments designed to investigate the sorption of two cationic metals Cu and Zn. The data from batch experiments fitted the Langmuir isotherm and so theoretical maximum binding capacities could be obtained. These values were compared with experimental values derived from the column experiments. The mechanisms involved in the immobilisation were also investigated.

Adsorption↗
PubMed2003

Can the Sino-nasal Outcome Test (SNOT-22) be used as a reliable outcome measure for successful septal surgery?

Septoplasty and submucous resection are common procedures in the UK. This study looks prospectively at 40 patients undergoing surgery at two hospitals. A pre- and postoperative assessment (3 months) was made using the Sino-nasal Outcome Test. This test was originally designed for rhinosinusitis but our study suggests that it is a useful tool in nasal septal surgery, in that it combines both nasal specific and general health questions, which can be analysed individually or together. Improvements in nasal obstruction (75%), facial pain (33%) and catarrh (10%) were noted.

Adult↗
PubMed2003

Mortality study of 18 000 patients treated with omeprazole.

BACKGROUND: The long term safety of potent gastric acid suppressive therapy has yet to be established. METHOD: General practice record review at a median interval of 26 months followed by retrieval of details of all deaths within four years using the UK National Health Service Central Registers in 17 936 patients prescribed omeprazole in 1993-1995. Death rates were compared with general population rates. RESULTS: Records of 17 489 patients (97.5%) were examined. A total of 12 703 patients received further scripts for antisecretory drugs, 8097 for omeprazole only (65.6%): 3097 patients have died. All cause mortality was higher in the first year (observed/expected (O/E) 1.44 (95% confidence intervals (CI) 1.34-1.55); p<0.0001) but had fallen to population expectation by the fourth year. There were significant mortality increases in the first year, falling to or below population expectation by the fourth year, for deaths ascribed to neoplasms (1.82 (95% CI 1.58-2.08); p<0.0001), circulatory diseases (1.27 (95% CI 1.13-1.43); p<0.0001), and respiratory diseases (1.37 (95% CI 1.12-1.64); p<0.001). Increased mortality ascribed to digestive diseases (2.56 (95% CI 1.87-3.43); p<0.0001) persisted, although reduced. Increased mortality rates for cancers of the stomach (4.06 (95% CI 2.60-6.04); p<0.0001), colon and rectum (1.40 (95% CI 0.84-2.18); p=0.075), and trachea, bronchus, and lung (1.64 (95% CI 1.19-2.19); p<0.01) seen in the first year had disappeared by the fourth year but that for cancer of the oesophagus had not (O/E 7.35 (95% CI 5.20-10.09) (p<0.0001) in year 1; 2.88 (95% CI 1.62-4.79) (p<0.001) in year 4). Forty of 78 patients dying of oesophageal cancer had the disease present at registration. Twenty seven of those remaining cases had clinical evidence of Barrett's disease, stricture, ulcer, or oesophagitis at registration (O/E 3.30 (95% CI 2.17-4.80)). Six deaths occurred in patients with hiatal hernia or reflux only (O/E 1.02 (95% CI 0.37-2.22)) and five in patients without oesophageal disease (O/E 0.77 (95% CI 0.25-1.80)). No relationships were detected with numbers of omeprazole scripts received. CONCLUSIONS: Increases in mortality associated with treatment are due to pre- existing illness, including pre-existing severe oesophageal disease. There was no evidence of an increased risk of oesophageal adenocarcinoma in those without oesophageal mucosal damage recorded at registration.

Adolescent↗
PubMed2003

Diagnosis and treatment of presumed STIs at Mexican pharmacies: survey results from a random sample of Mexico City pharmacy attendants.

OBJECTIVES: People in developing countries often seek medical advice for common ailments from pharmacies. As one example, pharmacists routinely diagnose and treat symptomatic sexually transmitted infections (STIs). We aimed to assess the quality of advice provided in Mexico City pharmacies by presenting hypothetical STI related syndromes and recording pharmacy attendants' suggested diagnoses and treatments. METHODS: We interviewed the first available attendant in each of a 5% random sample of Mexico City's pharmacies. We inquired about the training, age, and experience of the attendant and about the typical number of clients coming for treatment of suspected STIs. After considering three hypothetical case studies, attendants recommended diagnoses, treatments, and, sometimes, physician follow up. RESULTS: Most Mexico City "pharmacists" are actually clerks, with trained pharmacists rarely available on the premises. The average pharmacy attendant was 32 years old, with a median of 5 years' experience at that pharmacy, but very limited (if any) training. 62% reported seeing 10 or more clients with genital or vaginal infections per month. Depending on the case study, attendants provided appropriate diagnoses in 0-12% of cases, recommended appropriate treatments in 12-16% of cases, and suggested physician follow up for 26-67% of cases. CONCLUSIONS: In general, surveyed pharmacy personnel were unable to diagnose accurately or offer appropriate treatment advice when presented with classic, common STI symptoms. Given the volume of clients seeking advice from this source, training pharmacy attendants could significantly help to reduce the burden of disease associated with STIs in Mexico City.

Adolescent↗
PubMed2003

A comparison of the antimicrobial effects of four silver-containing dressings on three organisms.

OBJECTIVE: To compare the antimicrobial activity of four silver-containing dressings: Acticoat (Smith and Nephew), Actisorb Silver 220 (Johnson and Johnson), Avance (SSL International) and Contreet-H (Coloplast). METHOD: The dressings were tested against three micro-organisms: a Gram-positive bacterium, Staphylococcus aureus; a Gram-negative organism, Escherichia coli; and a yeast, Candida albicans, using three different techniques. Each dressing also had its silver content analysed. RESULTS: Acticoat is likely to produce the most rapid antimicrobial effect in vitro because of the rapid release of relatively large concentrations of highly active silver ions. Contreet-H has broadly similar antimicrobial activity to Acticoat, but has a slower onset of action. Actisorb Silver 220 appears to offer less prospect of killing bacteria within the wound itself, but the dressing is capable of removing micro-organisms from wound exudate and sequestering them until they are inactivated by the silver within the charcoal fibres. Little convincing evidence for any antimicrobial activity of Avance was found. CONCLUSION: Although caution must always be exercised when extrapolating the results of laboratory-based studies to the clinical situation, potentially important differences were detected in the antimicrobial activity of the four products examined. It is also possible that the silver ions released by the dressings may have effects on wound healing that are unrelated to their antimicrobial activity. Further work is needed to address this issue.

Bandages↗
PubMed2002

Long-time in-vivo metabolic monitoring following experimental brain contusion using proton magnetic resonance spectroscopy.

In a Sham-controlled study we applied proton magnetic resonance spectroscopy (1H-MRS) at 4.7 T to a model of experimental traumatic brain contusion. The time course of cerebral metabolite changes was monitored in serial investigation in 14 Sprague Dawley rats up to 4 weeks after trauma. 6 animals served as controls. 1H-MRS spectra were acquired from a voxel covering the hippocampus/basal ganglia ipsi and contralateral to the lesion. Metabolites ratios of the injured hemisphere were compared to those ipsilateral in Sham animals and to those of the contralateral side in the trauma animals. NAA/Cr ratio and Glu/Cr ratio, possible markers of neuronal loss, persistently decreased after trauma to a minimum of -40% and -20% versus controls, respectively. One week after trauma Cho/Cr ratio was strongly increased by 73%. This might indicate a high inflammatory activity at that time. Lac/Cr ratio showed long-lasting and continuing increases up to 2000% versus controls as a sign of permanently shifted posttraumatic energy metabolism. 1H-MRS proved to be a useful non-invasive method for in-vivo monitoring of posttraumatic metabolism also in models of brain contusion. In single cases however, accompanying haemorrhage can potentially prevent useful data acquisition.

Animals↗
PubMed2002

Determination of contusion and oedema volume by MRI corresponds to changes of brain water content following controlled cortical impact injury.

The time-course of brain contusion/oedema development as visualised by high-resolution MRI was compared to brain water content following experimental brain contusion. 36 Sprague-Dawley rats underwent Controlled Cortical Impact Injury (CCII), 24 served as controls. In 16 animals serial T2 weighted MRI investigations at 1 h, 4 h, 24 h and 7 d after CCII were performed, in 44 rats hemispheric brain water content was determined at the same time points by wet dry weight method. MRI lesion volume (mm3) and brain water content of injured hemisphere (%) showed for absolute and relative values a strictly parallel course. Significant posttraumatic increases had a maximum at 24 hours. Values on day 7 were below those of 1st h in both methods. The simple non-invasive MRI method quantifies contusion and surrounding penumbra according to elevated tissue water signal. The invasive wet dry weight method quantifies changes of hemispheric brain water content that are likely to take place in contusion core and surrounding penumbra. Therefore, from a theoretical aspect both methods seem comparable. Following experimental brain contusion, the simple MRI method might be an equally sufficient way to describe post-traumatic or post-therapeutic changes of lesion size and brain oedema.

Animals↗
PubMed2002

Traumatic subarachnoidal hemorrhage in the developing rat.

The aim of the present study was to utilize an experimental traumatic subarachnoidal hemorrhage model in the developing rat. Diffuse brain injury was produced in intubated and ventilated 21 to 25 days old Sprague-Dawley rats (N = 10) using a modification (1 m/100 g) of the Marmarou-model. Before induction of the injury heparin was administered i.v. and antagonised after injury by protamine. Mean arterial blood pressure and intracranial pressure was measured continuously. Histopathological investigations were performed. The results were compared to readings in adult animals (N = 12) subjected to a 1.5 m/500 g injury. In the developing rat ICP increased immediately following injury from 11.4 +/- 2.1 mm Hg to 55.9 +/- 20.3 mm Hg. It remained elevated till the end of the experiment 1 h after injury. MABP increased from 79.8 +/- 8.7 mm Hg to 100.2 +/- 21.7 mm Hg immediately following injury, returning to 61.3 +/- 28.7 mm Hg at the end of the experiment resulting in a marked decrease of CPP. The mortality rate was 60%. All brains showed a severe subarachnoidal hemorrhage in the basal cisterns. The increase of ICP following injury is attributable to the bleeding similar as in adult animals. The high mortality is due to the marked decrease of CPP. Rat pups are more vulnerable to t-SAH compared to adult rats.

Aging↗
PubMed2002

Paracrine activation of extracellular signal-regulated kinase in a simple in vitro model of wounded osteoblasts.

The immediate signal-transduction response of osteoblasts to acute trauma is poorly characterized. We have developed a simple in vitro model for osteoblast trauma to investigate aspects of the molecular mechanisms of wound healing in bone. Herein we report the specific, rapid, and transient phosphorylation of extracellular signal-regulated kinase (ERK) 1 and 2 in osteoblasts as a response to disruption ("wounding") of a confluent monolayer. The mitogen-activated protein kinase (MAPK) cascades of p38 and stress-activated protein kinase/c-jun N-terminal kinase (SAPK/JNK) were not activated by this perturbation. The response to wounding was equivalent to the activation of ERK by the addition of exogenous growth factors, and the perturbation-dependent phosphorylation of ERK can be suppressed by an inhibitor of heparin-binding growth factors. Conditioned media from wounded monolayers can induce the phosphorylation of ERK in unperturbed monolayers. Using immunohistochemistry, it was demonstrated that the cells with increased levels of phosphorylated ERK were not localized to the wound edges. These results indicate that ERK activation is the result of an autocrine/paracrine response by osteoblasts to trauma. We speculate that osteoblasts respond to trauma with the release of soluble factors as part of an autocrine/paracrine modulation of the wound-healing process in bone.

3T3 Cells↗
PubMed2002

Human granulocytic ehrlichiosis in a renal allograft recipient: review of the clinical spectrum of disease in solid organ transplant patients.

BACKGROUND: Ehrlichiosis is a recently described zoonotic infection with two major expressions: human granulocytic ehrlichiosis (HGE) and human monocytic ehrlichiosis (HME). The organisms associated with HGE and HME have been detected in a tick vector in several regions of United States and cases of ehrlichiosis have been reported in the general population. METHODS: We report a case of HGE in a renal allograft recipient and review the clinical spectrum of disease in solid organ transplant recipients and the epidemiological basis for risk. RESULTS: Our patient demonstrated the typical epidemiological, clinical and laboratory features of human granulocytic ehrlichiosis and responded to treatment with doxycycline. CONCLUSIONS: Human ehrlichiosis should be considered in the differential diagnosis of patients with solid organ transplants, who present with fever and thrombocytopenia. The incidence of ehrlichiosis in the solid organ transplant population is similar to that in the United States general population. As reported in immunocompetent patients, prompt diagnosis and treatment results in the rapid resolution of symptoms in transplanted individuals.

Aged↗
PubMed2002

Prevalence of erectile dysfunction: a systematic review of population-based studies.

A systematic review was conducted on the prevalence of erectile dysfunction (ED) in the general population. Studies were retrieved which reported prevalence rates of ED in the general population. Using a specially developed criteria list, the methodological quality of these studies was assessed and data on prevalence rates were extracted. We identified 23 studies from Europe (15), USA (5), Asia (2) and Australia (1). On our 12-item criteria list, the methodological quality ranged from 5 to 12. The prevalence of ED ranged from 2% in men younger than 40 y to 86% in men 80 y and older. Comparison between prevalence data is hampered by major methodological differences between studies, particularly in the use of various questionnaires and different definitions of ED. We stress the importance of providing all necessary information when reporting on the prevalence of ED. Moreover, international studies should be conducted to establish the true prevalence of ED across countries.

Age Distribution↗
PubMed2002

Intramuscular lipomatosis of tongue.

A rare case of intramuscular lipomatosis of the tongue with intramuscular invasion in a 42 year old man is presented. The literature is reviewed and the clinical features, pathology, and treatment are discussed briefly.

Adult↗
PubMed2002

The Decorin gene 179 allelic variant is associated with a slower progression of renal disease in patients with type 1 diabetes.

UNLABELLED: Background genetic factors may influence the variability in the rate of progression of kidney disease in type 1 diabetes. In diabetes, progressive mesangial matrix expansion and glomerular sclerosis are, to a large extent, mediated by TGF-beta1. Decorin, a proteoglycan which is a component of the extracellular matrix, regulates TGF-beta1 activity and expression. We have examined the relationship between the 179/183/185 polymorphism of the Decorin gene and the progression of diabetic nephropathy. METHODS: From a cohort of 175 European patients with diabetic nephropathy, we studied 79 patients who were selected because they had a follow-up of at least 2 years (average 6.5 years; range: 2.5-15 years), and regular measurements of serum creatinine on 5 or more occasions. Creatinine clearance (CrCl) calculated from serum creatinine concentration was used as a measure of derived glomerular filtration rate (dGFR). All patients were on antihypertensive therapy. RESULTS: The rate of dGFR decline in the whole cohort was [median (range)] 4.6 (-3.8 to 18) ml/min/year. No patient with 185 allele was found. Patients with 179/183 and 179/179 genotype (n = 14), who were considered together and named 179 carriers, had a slower rate of GFR decline [2.1 (0.06-11.7) ml/min/year] as compared to patients with Decorin 183/183 genotype (n = 65) [5.6 (-3.8 to 18) ml/min/year; p < 0.001]. In addition, when considering individual data, patients carrying the 179 allele had a 3.0 (95%CI: 1.8-4.2)-fold higher probability to be slow progressors (i.e. GFR decline below the median). This difference could not be accounted for by differences in duration of disease, type and duration of antihypertensive therapy, albumin excretion rate, blood glucose or blood pressure control. In a multivariate logistic analysis albumin excretion rate (p < 0.001), mean arterial pressure (p = 0.07) and Decorin gene polymorphism (p = 0.036), but not HbA1c, were independently correlated with the rate of dGFR fall. CONCLUSION: The 179 allele variant of the Decorin gene is related to a slower progression of DN in type 1 diabetic patients with albuminuria and receiving antihypertensive therapy.

Adult↗