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Biomedical subjects

M Hall

Publications and source records attributed to M Hall.

At least 19 recordsLinked to original sources
PubMed2006

Evolution of fetal ultrasonography.

The authors wish to highlight the evolution that has occurred in fetal ultrasound in recent years. A first significant evolution lies in the increasing contribution of first trimester ultrasound for the detection of fetal anomalies. Malformations of several organs and systems have been diagnosed during the first trimester. Furthermore the systematic measurement of the fetal neck translucency has led to increasing rate of detection of aneuploidies and heart malformations. For several years now, three-dimensional (3D) and 4D ultrasound (US) have been used as a complementary tool to 2D US for the evaluation of fetal morphology. This brings an improved morphologic assessment of the fetus. Applications of the techniques are increasing, especially for the fetal face, heart and extremities. The third field where fetal US is continuously providing important information is the knowledge of the natural history of diseases. This has brought significant improvement in the postnatal management of several diseases, especially urinary tract dilatation and broncho-pulmonary malformation.

Congenital Abnormalities↗
PubMed2006

A randomised controlled trial of ablation of Barrett's oesophagus with multipolar electrocoagulation versus argon plasma coagulation in combination with acid suppression: long term results.

BACKGROUND: Many modalities have been used to ablate Barrett's oesophagus (BO). However, long term results and comparative effectiveness are unknown. AIMS: Our aim was to compare the long term efficacy of achieving complete reversal (endoscopic and histological) between multipolar electrocoagulation (MPEC) and argon plasma coagulation (APC) in BO patients and assess factors influencing successful ablation. METHODS: Patients with BO, 2-6 cm long, underwent 24 hour pH testing on proton pump inhibitor (PPI) therapy. Patients were then randomised by BO length to undergo ablation with MPEC or APC every 4-8 weeks until endoscopic reversal or maximal of six treatment sessions. RESULTS: Thirty five BO patients have been followed for at least two years following endoscopic ablation, 16 treated with MPEC and 19 with APC. There was complete reversal of BO in 24 patients (69%); 75% with MPEC and 63% with APC (p = 0.49). There was no difference in the number of sessions required in the two groups. There was no difference in age, pH results, BO length, PPI dose, or hiatal hernia size between patients with and without complete reversal. One patient developed an oesophageal stricture but there were no major complications such as bleeding or perforation. CONCLUSIONS: In BO patients treated with MPEC or APC in combination with acid suppression, at long term follow up, complete reversal of BO can be maintained in approximately 70% of patients, irrespective of the technique. There are no predictors associated with achieving complete reversal of BO. Continued surveillance is still indicated in the post ablative setting. As yet, these techniques are not ready for clinical application (other than for high grade dysplasia or early oesophageal adenocarcinoma) and cannot be offered outside the research arena.

Adult↗
PubMed2005

Supranormal renal function in unilateral hydronephrosis: does it represent true hyperfunction?

The existence of supranormal differential renal function in unilateral hydronephrosis remains controversial. While some authors consider it as fact, others believe that it is just a technical artifact. Within our department, chromium-51 ethylene diamine tetra-acetic acid (Cr-EDTA) renal clearance is systematically performed in conjunction with technetium-99m mercaptoacetyltriglycine (MAG3) renograms to derive an absolute single kidney glomerular filtration rate (SKGFR). Our data allows us to ascertain whether supranormal differential renal function in unilateral hydronephrosis might be due to hypofunction of the contralateral kidney. Children with marked unilateral hydronephrosis were selected from a large database of MAG3 diuretic(s) renograms. We excluded patients with posterior urethral valves, duplex anomalies, neurogenic bladder, solitary kidney, and those who underwent any previous urological surgery. We also excluded children who had an early furosemide injection (F0 procedure), selecting only those having received furosemide at the end of the renogram (F+20 test). Seventy-three patients (92 renograms) fulfilled these criteria. Differential renal function was calculated using the integral method. Hydronephrotic kidney with a relative uptake > or =55% was defined as supranormal. Six renograms (four patients) demonstrated supranormal relative function on the hydronephrotic side. However, the SKGFR of these kidneys was in all cases within the range of normal values, while the contralateral side demonstrated borderline low SKGFR. Increased relative function on the side of the hydronephrotic kidney is relatively infrequent. When it occurs, it may be related to a borderline hypofunction of the contralateral kidney.

Chelating Agents↗
PubMed2005

Lack of predictors of normalization of oesophageal acid exposure in Barrett's oesophagus.

BACKGROUND: Barrett's oesophagus patients may continue to have abnormal oesophageal acid exposure on proton pump inhibitor therapy. The effect of factors such as Barrett's oesophagus length, hiatal hernia size and Helicobacter pylori infection on intra-oesophageal pH in Barrett's oesophagus patients has not been adequately studied. AIM: To evaluate oesophageal acid exposure in a large Barrett's oesophagus population on b.d. proton pump inhibitor therapy and determine clinical factors predicting normalization of intra-oesophageal pH on therapy. METHODS: Barrett's oesophagus patients were studied using 24 h pH monitoring to evaluate intra-oesophageal acid suppression on b.d. dosing of rabeprazole. RESULTS: Forty-six Barrett's oesophagus patients completed the study. Median total percentage time pH < 4 was 1.05% (range: 0-29.9%) in the entire group and respective values for upright and supine percentage time pH < 4 were 1.15% and 0%. However, 34 of the Barrett's oesophagus patients (73.9%) had a normal pH study (median total percentage time pH < 4: 0.2%) and 12 patients (26.1%) had an abnormal result (median total percentage time pH < 4: 9.3%). There were no significant differences between patients with a normal and abnormal 24 h pH result with respect to age, Barrett's oesophagus length, hiatal hernia size and presence of H. pylori infection. CONCLUSIONS: Approximately 25% of Barrett's oesophagus patients continue to have abnormal total intra-oesophageal pH profiles despite b.d. proton pump inhibitor therapy. Factors such as age, Barrett's oesophagus length and hiatal hernia size cannot be used to predict persistent abnormal intra-oesophageal pH on proton pump inhibitor.

2-Pyridinylmethylsulfinylbenzimidazoles↗
PubMed2005

A potent nonporphyrin class of photodynamic therapeutic agent: cellular localisation, cytotoxic potential and influence of hypoxia.

We have developed a totally new class of nonporphyrin photodynamic therapeutic agents with a specific focus on two lead candidates azadipyrromethene (ADPM)01 and ADPM06. Confocal laser scanning microscopy imaging showed that these compounds are exclusively localised to the cytosolic compartment, with specific accumulation in the endoplasmic reticulum and to a lesser extent in the mitochondria. Light-induced toxicity assays, carried out over a broad range of human tumour cell lines, displayed EC50 values in the micro-molar range for ADPM01 and nano-molar range for ADPM06, with no discernable activity bias for a specific cell type. Strikingly, the more active agent, ADPM06, even retained significant activity under hypoxic conditions. Both photosensitisers showed low to nondeterminable dark toxicity. Flow cytometric analysis revealed that ADPM01 and ADPM06 were highly effective at inducing apoptosis as a mode of cell death. The photophysical and biological characteristics of these PDT agents suggest that they have potential for the development of new anticancer therapeutics.

Apoptosis↗
PubMed2005

How to interpret a deterioration of split function?

OBJECTIVE: A drop of split renal function often constitutes a criterion for pyeloplasty in hydronephrosis since it is considered as representing deterioration of the affected kidney. The aim of this work was to determine, in a selected population of patients with a drop of split function of at least 5%, if the evolution of single kidney glomerular filtration rate (SKGFR) was parallel to the one of split renal function. METHODS: From a large data basis, we found retrospectively only 29 children (10 below and 19 above two years of age at first examination) having had at least two Tc-99m mertiatide (Tc-99m MAG3) renographic explorations for various urological diseases, with a decrease of split function of at least 5% between the two examinations. Evolution of split function was compared to evolution of SKGFR obtained by means of the combination of Tc-99m MAG3 split function and overall glomerular filtration rate as given by the chromium Cr 51 ethylenediamine tetraacetic acid (EDTA) clearance. RESULTS: For the group above two years of age, SKGFR increased or remained stable in 63% of the cases, while in the children less than 2 years of age, a decrease of SKGFR was never observed, according to the maturation of overall GFR in this age group. Thus, the decrease of split function was not necessarily associated with a similar decrease of SKGFR. CONCLUSION: In patients with unilateral or bilateral urological disorders, deterioration of split renal function does not necessary correspond to a loss of function of the affected kidney. SKGFR often modifies the interpretation of split function.

Chelating Agents↗
PubMed2005

Physiological profile in relation to playing position of elite college Gaelic footballers.

OBJECTIVE: To examine the physiological profile, and its relation to playing position, of elite college Gaelic footballers. METHOD: The subjects were 28 elite Gaelic footballers (12 backs, 12 forwards, and four midfielders; mean (SD) age 21 (1.67) years), who won a major intervarsity tournament (Sigerson Cup) three times in succession. RESULTS: There was general similarity among the members of the team, probably the result of a typical, common training programme. The team means for stature (1.81 (0.05) m), body mass index (81.6 (6.5)) and percentage body fat (14.5 (3.1)%), power output by Wingate test (absolute power 912 (152) W or 10.72 (1.6) W/kg) and sit and reach test (22.3 (5.5) cm) displayed no significant differences when analysed according to playing position. However, midfielders did have significantly larger body mass than backs (p<0.05) and greater maximal oxygen consumption (p<0.01) and greater vertical jumping ability than backs and forwards (vertical jump power output, p<0.01; vertical jump, p<0.01). Midfielders also had greater absolute handgrip strength (p<0.01). CONCLUSION: The differences exhibited by midfielders despite identical training suggests that they stem from physiological adaptation to competition rather than training.

Adult↗
PubMed2005

The impact on patient trust of legalising physician aid in dying.

OBJECTIVE: Little empirical evidence exists to support either side of the ongoing debate over whether legalising physician aid in dying would undermine patient trust. DESIGN: A random national sample of 1117 US adults were asked about their level of agreement with a statement that they would trust their doctor less if "euthanasia were legal [and] doctors were allowed to help patients die". RESULTS: There was disagreement by 58% of the participants, and agreement by only 20% that legalising euthanasia would cause them to trust their personal physician less. The remainder were neutral. These attitudes were the same in men and women, but older people and black people had more agreement that euthanasia would lower trust. However, overall, only 27% of elderly people (age 65+) and 32% of black people thought that physician aid in dying would lower trust. These views differed with physical and mental health, and also with education and income, with those having more of these attributes tending to view physician aid in dying somewhat more favourably. Again, however, overall views in most of these subgroups were positive. Views about the effect of physician aid in dying on trust were significantly correlated with participants' underlying trust in their physicians and their satisfaction with care. In a multivariate regression model, trust, satisfaction, age, and white/black race remained independently significant. CONCLUSION: Despite the widespread concern that legalising physician aid in dying would seriously threaten or undermine trust in physicians, the weight of the evidence in the USA is to the contrary, although views vary significantly.

Adult↗
PubMed2004

Trichinella pseudospiralis foci in Sweden.

In Sweden, the prevalence of Trichinella infection in domestic pigs has greatly decreased since the 1970s, with no reports in the past 4 years. However, infected wild animals continue to be found. The objective of the present study was to identify the species of Trichinella present in animals of Sweden, so as to contribute to the knowledge on the distribution area and hosts useful for the prevention and control of this zoonosis. In the period 1985-2003, Trichinella larvae were detected in the muscles of 81/1800 (4.5%) red foxes (Vulpes vulpes), 1/6 (16.7%) arctic fox (Alopex lagopus), 1/7 (14.3%) wolf (Canis lupus), 10/200 (5.0%) lynxes (Lynx lynx), 4/8000 (0.05%) wild boars (Sus scrofa), and 27/66 x 10(6) (0.000041%) domestic pigs. All four Trichinella species previously found in Europe were detected (Trichinella spiralis, T. nativa, T. britovi and T. pseudospiralis). The non-encapsulated species T. pseudospiralis was detected in three wild boars from Holo (Stockholm area) and in one lynx from Froso (Ostersund area), suggesting that this species is widespread in Sweden. These findings are consistent with those of a study from Finland, both for the unexpected presence of T. pseudospiralis infection and the presence of the same four Trichinella species, suggesting that this epidemiological situation is present in the entire Scandinavian region. The widespread diffusion of T. pseudospiralis in the Scandinavian region is also important in terms of it potential impact on public health, given that human infection can occur and the difficulties to detect it by the trichinelloscopic examination.

Animals↗
PubMed2003

Successful toxoplasmosis prophylaxis after orthotopic cardiac transplantation with trimethoprim-sulfamethoxazole.

BACKGROUND: The efficacy of trimethoprim-sulfamethoxazole (TMP/SMX) in the prevention of toxoplasmosis after orthotopic cardiac transplantation has been the subject of some controversy, with many transplant groups preferring to use the combination of pyrimethamine and sulfadiazine. Although effective, this latter regimen does not offer equal protection against other pathogens, such as or. To assess the value of TMP/SMX, we reviewed the experience in our heart transplant patients, all of whom received TMP/SMX (160/800 mg) three times weekly for approximately 8 months after transplantation. METHODS: We report on 417 orthotopic cardiac transplants during a 17-year period. We have 100% one-year patient follow-up after transplantation. Data was collected on pretransplantation donor and recipient anti- serology, immunosuppression, allograft rejection, survival, yearly posttransplantation anti- serology, development of acute toxoplasmosis, and the occurrence of other infections. RESULTS: In this cohort, acute toxoplasmosis developed after transplantation in one case (0.2%). Among the highest risk patients (D+R-) who were treated for at least one episode of rejection, the risk of acute toxoplasmosis was 5% (1 of 22 patients). No change in survival was found between the different anti- IgG serogroups (D-R-, D-R+, D+R-, or D+R+). Anti- IgG seroconversion occurred in eight -seronegative recipients after transplantation; all patients, except the case already noted, were asymptomatic and required no specific anti- therapy. No cases of, or infections were identified. Five proven and two suspected cases of pneumonia were found (only 2 of these 7 patients were receiving TMP/SMX at the time of pneumonia diagnosis). CONCLUSIONS: These data demonstrate that TMP/SMX prophylaxis (160/800 mg) three times per week is effective prophylaxis after orthotopic cardiac transplantation and has prophylactic benefits against other posttransplantation opportunistic pathogens.

Anti-Infective Agents↗
PubMed2003

Degradation of extracellular matrix components by defined proteinases from the greenbottle larva Lucilia sericata used for the clinical debridement of non-healing wounds.

BACKGROUND: Larvae of the greenbottle fly Lucilia sericata are used routinely for the clinical treatment of difficult necrotic and infected wounds. Degradation by proteinases contained in larval excretory/secretory (ES) products is thought to contribute to wound debridement by removal of dead tissue. However, proteinase activity may also affect host tissue remodelling processes. OBJECTIVES: To identify proteolytic enzymes derived from L. sericata ES products with activities against fibrin and extracellular matrix (ECM) components. METHODS: Larval proteinase activities were assayed in vitro using class-specific substrates and inhibitors. Their action against fibrin and ECM components was examined using sodium dodecyl sulphate-polyacrylamide gel electrophoresis. RESULTS: Three classes of proteolytic enzyme were detected in the secretions using fluorescein isothiocyanate-labelled casein as a model substrate. The predominant activity belonged to serine proteinases (pH optima 8-9) of two different subclasses (trypsin-like and chymotrypsin-like), with a weaker aspartyl proteinase (pH 5) and a metalloproteinase (pH 9) with exopeptidase characteristics also present. Using skin-relevant ECM components as substrates L. sericata ES products solubilized fibrin clots and degraded fibronectin, laminin and acid-solubilized collagen types I and III. Hydrolysis of ECM macromolecules was inhibited by preincubating ES products with phenylmethylsulphonyl fluoride but not 4-amidinophenylmethylsulphonyl fluoride, indicating that degradation was due to the 'chymotrypsin-like' serine proteinase. CONCLUSIONS: These data suggest that a combination of L. sericata ES proteinases involving chymotrypsin-like and trypsin-like activities could potentially influence wound healing events when maggots are introduced into necrotic and infected wounds, with the chymotrypsin-like activity involved in the remodelling of ECM components.

Animals↗
PubMed2003

Near misses: a useful adjunct to maternal death enquiries.

In developed countries where maternal death is rare, the factors surrounding the death are often peculiar to the event and are not generalizable, making analysis of maternal deaths less useful. Near misses are defined as pregnant women with severe life-threatening conditions who nearly die but, with good luck or good care, survive. Incorporation of near misses into maternal death enquiries would strengthen these audits by allowing for more rapid reporting, more robust conclusions, comparisons to be made with maternal deaths, reinforcing lessons learnt, establishing requirements for intensive care and calculating comparative indices. The survival of a pregnant woman is dependent on the disease, her basic health, the health care facilities and personnel of the health care system. The criteria currently used to identify a near miss vary greatly. However, areas with similar health care facilities, medical records and personnel should be able to agree on suitable criteria, making their incorporation into maternal death enquiries feasible.

Cause of Death↗