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Biomedical subjects

J Morgan

Publications and source records attributed to J Morgan.

At least 19 recordsLinked to original sources

Surveillance of insecticide resistance in head lice using biochemical and molecular methods.

Treatment of head louse infection is primarily through topical insecticides. However, there is growing evidence of resistance. A representative population sample was tested using biochemical and molecular methods; it was shown that, in Wales, treatments containing pyrethroids are likely to be less effective in controlling head louse infection than those containing organophosphates.

Animals↗

Validation of a rapid enzyme immunoassay for the quantitation of retinol-binding protein to assess vitamin A status within populations.

OBJECTIVE: To compare the prevalence of vitamin A deficiency (VAD) among Cambodian preschool children as determined by the retinol-binding protein-enzyme immunoassay (RBP-EIA) and direct measurement of serum retinol by high-performance liquid chromatography (HPLC). SETTING AND SUBJECTS: Sera from 359 children were randomly selected from archived specimens collected in a national VAD prevalence survey in Cambodia. METHODS: Sera were first analyzed for retinol content by HPLC and then subjected to analysis using RBP-EIA to determine serum RBP concentrations. National Institute of Standards and Technology and control sera were used to ensure quality and accuracy for each set of analyses. To classify VAD, the same cutoff point of <0.70 micromol/l was employed for each indicator. RESULTS: Overall, the prevalence of VAD based on serum retinol was 22.3% (95% confidence interval (CI): 18.0, 26.6), whereas the RBP-EIA indicated a VAD prevalence of 20.9% (95% CI: 16.7, 25.1). A simple linear regression model indicated an R2 of 0.79, and a receiver operating curve analysis revealed an area under the curve of 0.92. CONCLUSIONS: We found no significant difference between the results of RBP-EIA compared to retinol analyzed by HPLC in estimating the prevalence of VAD. Use of the test could enable public health authorities to assess the extent of VAD and track progress in control programs in resource-poor settings.

Area Under Curve↗

Role of interleukin (IL-10) in probiotic-mediated immune modulation: an assessment in wild-type and IL-10 knock-out mice.

While the impact of Bifidobacterium infantis 35624 and other probiotics on cytokines has been shown in established colitis, the effects of B. infantis consumption in pre-inflammation of interleukin (IL)-10 knock-out (KO) mice and on the wild-type (WT) C57Bl/6 mice have not been well demonstrated. The objective of this study was to examine cytokine responses in mucosal and systemic lymphoid compartments of IL-10 KO mice early in disease and to compare with control WT mice. Mice were fed B. infantis or placebo for 5 weeks and culled prior to the onset of chronic intestinal inflammation (12-14 weeks). The spleen, Peyer's patches and intestinal mucosa were removed and stimulated with various bacterial stimuli. Cytokine levels were measured by enzyme-linked immunosorbent assay. While basal intestinal and systemic cytokine profiles of WT and IL-10 KO mice were similar, transforming growth factor (TGF)-beta was reduced in the spleen of IL-10 KO mice. Following probiotic consumption, interferon (IFN)-gamma was reduced in the Peyer's patch of both WT and IL-10 KO mice. Alterations in IFN-gamma in the Peyer's patches of WT mice (enhancement) versus IL-10 KO (reduction) were observed following in vitro stimulation with salmonella. Differential IL-12p40, CCL2 and CCL5 responses were also observed in IL-10 KO mice and WT mice. The cytokine profile of IL-10 KO mice in early disease was similar to that of WT mice. The most pronounced changes occurred in the Peyer's patch of IL-10 KO mice, suggesting a probiotic mechanism of action independent of IL-10. This study provides a rationale for the use of B. infantis 35624 for the treatment of gastrointestinal inflammation.

Animals↗

The positive predictive value of diagnostic ultrasound for occult herniae.

INTRODUCTION: The aim of this study is to ascertain the accuracy of diagnostic ultrasound in the assessment of the occult abdominal and groin herniae. The authors have previously demonstrated its efficacy in diagnosing the type of clinical groin herniae but occult herniae provide a further diagnostic problem. PATIENTS AND METHODS: A total of 113 consecutive patients were referred prospectively for ultrasound examinations with clinically suspected occult herniae. All positive scans were offered surgery whilst the negative results were offered further imaging or other diagnostic tests depending on the clinical criteria. The end point for negative scans was based on 18-month follow-up or resolution of symptoms. RESULTS: Overall, 59 scans showed positive results for herniae and 56 of these had surgery. In the other three patients, two refused an operation, and one had no hernia detected at operation. In the remaining 57 scans, ultrasound offered alternative soft tissue diagnoses in 23 patients and surgical/endoscopic diagnoses accounted for a further 8 patients. CONCLUSIONS: Ultrasound offered a diagnosis for the symptomology in 82 patients (70.6%) of which 59 were herniae. The positive predictive value for hernia is 98.3%. Twenty-six patients with no diagnosis or confirmation of herniae on follow-up showed symptom resolution in 22 cases, and four patients were treated by the pain clinic.

Adult↗

Familial hypercholesterolaemia commonly presents with Achilles tenosynovitis.

BACKGROUND: Patients with heterozygous familial hypercholesterolaemia (HeFH) develop tendon xanthomata (TX), most commonly in their Achilles tendons. Even before tendons are chronically enlarged, tenosynovitis may occur and medical advice be sought. Untreated HeFH carries a high risk of premature coronary heart disease, which can be ameliorated by early diagnosis. OBJECTIVE: To determine the prevalence of episodes of Achilles tendon pain in HeFH before its diagnosis. METHODS: Patients with definite HeFH (Simon Broome criteria) attending a lipid clinic were identified. They completed a questionnaire asking about symptoms relating to their Achilles tendons. Unaffected spouses or cohabiting partners served as controls. RESULTS: 133 patients (47% men) and 87 controls (51% men) participated. TX had been recognised by the referring physicians in <5% of cases. However, 62 (46.6% (95% confidence interval (CI) 38.1 to 55.1)) patients had experienced one or more episodes of pain in one or both Achilles tendons lasting >3 days, whereas only 6 (6.9% (1.6 to 12.2)) controls had done so (difference p<0.001; likelihood ratio 6.75). Typically, in the patients with HeFH the pain lasted 4 days (median). It was described as severe or very severe in 24/62 (38.7% (30.4 to 47.0)) patients with HeFH, but never more than moderate in controls. 35 (26.3% (18.8 to 33.8)) patients with HeFH had consulted a doctor about Achilles tendon pain, but in no case had this led to a diagnosis of HeFH. None of the controls had consulted a doctor. CONCLUSIONS: Measurement of serum cholesterol in patients presenting with painful Achilles tendon could lead to early diagnosis of HeFH.

Achilles Tendon↗

Failure rate of frontal versus parietal approaches for proximal catheter placement in ventriculoperitoneal shunts: revisited.

Early studies on ventriculoperitoneal shunt malfunctions demonstrated that proximal catheter obstruction was the most common cause for shunt malfunction and choroid plexus was the primary culprit for catheter obstruction. Subsequently, several studies were performed using stereotactic and endoscopic guidance systems to assist with optimal placement of proximal shunt catheters. Surgeons collectively agree that optimum placement of the proximal catheter tip is away from choroid plexus in the frontal horn. To achieve this catheter placement, neurosurgeons typically choose a frontal or parietal approach. Two previous studies comparing parietal and frontal shunt failure rates in the pediatric population have different conclusions. Thus, we decided to compare proximal catheter failure rates of frontal versus parietal approaches on 117 patients (ages ranging from 1 month to 80 years) who had undergone ventriculoperitoneal shunt placement at our institution. Statistical analysis demonstrated a significantly higher malfunction rate in the patients less than 3 years of age and a lower overall malfunction rate in patients shunted for normal pressure hydrocephalus. Surprisingly, there was no significant difference between the two surgical approaches. Thus, we concluded after reviewing the literature, that regardless of the initial surgical approach, the most important variable in shunt malfunction appears to be the final destination of the catheter tip in relation to the choroid plexus.

Adolescent↗

Incidence of invasive aspergillosis following hematopoietic stem cell and solid organ transplantation: interim results of a prospective multicenter surveillance program.

The incidence of invasive aspergillosis was estimated among 4621 hematopoietic stem cell transplants (HSCT) and 4110 solid organ transplants (SOT) at 19 sites dispersed throughout the United States, during a 22 month period from 1 March 2001 through 31 December 2002. Cases were identified using the consensus definitions for proven and probable infection developed by the Invasive Fungal Infections Cooperative Group of the European Organization for Research and Treatment of Cancer and the Mycoses Study Group of the National Institute of Allergy and Infectious Diseases. The cumulative incidence (CI) of aspergillosis was calculated for the first episode of the infection that occurred within the specified time period after transplantation. To obtain an aggregate CI for each type of transplant, data from participating sites were weighted according to the proportion of transplants followed-up for specified time periods (four and 12 months for HSCT; six and 12 months for SOT). The aggregate CI of aspergillosis at 12 months was 0.5% after autologous HSCT, 2.3% after allogeneic HSCT from an HLA-matched related donor, 3.2% after transplantation from an HLA-mismatched related donor, and 3.9% after transplantation from an unrelated donor. The aggregate CI at 12 months was similar following myeloablative or non-myeloablative conditioning before allogeneic HSCT (3.1 vs. 3.3%). After HSCT, mortality at 3 months following diagnosis of aspergillosis ranged from 53.8% of autologous transplants to 84.6% of unrelated-donor transplants. The aggregate CI of aspergillosis at 12 months was 2.4% after lung transplantation, 0.8% after heart transplantation, 0.3% after liver transplantation, and 0.1% after kidney transplantation. After SOT, mortality at three months after diagnosis of aspergillosis ranged from 20% for lung transplants to 66.7% for heart and kidney transplants. The Aspergillus spp. associated with infections after HSCT included A. fumigatus (56%), A. flavus (18.7%), A. terreus (16%), A. niger (8%), and A. versicolor (1.3%). Those associated with infections after SOT included A. fumigatus (76.4%), A. flavus (11.8%), and A. terreus (11.8%). In conclusion, we found that invasive aspergillosis is an uncommon complication of HSCT and SOT, but one that continues to be associated with poor outcomes. Our CI figures are lower compared to those of previous reports. The reasons for this are unclear, but may be related to changes in transplantation practices, diagnostic methods, and supportive care.

Aspergillosis↗

Observer variability in the histopathological reporting of core biopsies of papillary breast lesions is reduced by the use of immunohistochemistry for CK5/6, calponin and p63.

AIM: To investigate agreement on core biopsy diagnosis of papillary breast lesions, which is acknowledged as a difficult area, and to determine the effect of the use of immunohistochemistry (IHC) to assist diagnosis. STUDY DESIGN: Haematoxylin and eosin (H&E) sections of 129 core biopsies of papillary breast lesions were circulated to four observers who categorized each case as: B2 (benign), B3a (epithelial proliferation, probably benign but requiring biopsy), B3b (epithelial proliferation with cytological or architectural atypia), B4 (probably malignant but insufficient material or artefact to allow diagnosis), B5 (malignant papillary lesion). In all cases (n = 127) IHC was performed for cytokeratin (CK) 5/6, calponin, p63 (myoepithelial markers), and slides recirculated. RESULTS: There was unanimous agreement in 44% of cases on H&E only which rose to 91% after the use of IHC. Overall, unweighted kappa (Ku; five categories) rose from 0.54 to 0.91. The main effect of IHC was to reduce the use of intermediate categories (B3a, B3b and B4) and allow definitive diagnosis (B2 or B5). CONCLUSION: Agreement on H&E sections alone in papillary core biopsies of breast is only 44% (Ku = 0.54) but is significantly increased to 91% (Ku = 0.91) by the use of IHC for CK5/6, calponin and p63.

Biomarkers, Tumor↗

Wolf-Hirschhorn syndrome--two case-study reports focusing particularly on long-term survival.

BACKGROUND: The clinical features of this rare chromosomal syndrome are described in two individuals. Our limited knowledge of the natural history of this disorder has made it difficult to counsel parents as well as outline specific treatment and management plans. METHOD: Interviews were undertaken with subjects, carers and next of kin, and the literature was searched. RESULTS: Pertinent features of the syndrome are reported. MAIN CONCLUSIONS: These two cases highlight that long-term survival may occur and that accurate diagnosis is paramount so that healthcare professionals are able to provide accurate information.

Adult↗

Management of incidental hyperglycaemia in acute medical emergencies.

AIMS: To assess whether compliance with management guidelines for hyperglycaemia in acute medical emergencies was affected by prior diagnosis of diabetes, and to assess the effect of an educational campaign upon management. METHODS: Prospective study of management of adult patients admitted to an acute medical admissions unit in 2002, with repeat in 2003 after an educational campaign. RESULTS: The management of 251 patients in 2002 and 357 patients in 2003 was examined. In patients with no prior diagnosis of diabetes, unsatisfactory management was observed in 60% compared with only 30% of those with known diabetes (P < 0.02). In 2003 these proportions fell to 46 and 16%, respectively, but remained significantly different (P < 0.02). Overall, 30 of 70 (42.9%) patients with hyperglycaemia were managed strictly according to the guidelines in 2002 compared with 33 out of 59 (55.9%) in 2003 (P = 0.14). Satisfactory management was delivered in 55.7% in 2002 and 78% in 2003 (P < 0.01). CONCLUSIONS: The reluctance of doctors to manage incidental hyperglycaemia in acute medical admissions was especially common when the patient was not known to have diabetes. This was only modestly improved by an educational campaign, even though this group are known to have a greater response in terms of morbidity and mortality. Widespread debate of this issue is required to minimize morbidity and mortality due to hyperglycaemia.

Acute Disease↗

Cell-cell contact and membrane spreading in an ultrasound trap.

An ultrasonic standing wave trap [Langmuir 19 (2003) 3635] in which the morphologies of 2-D latex-microparticle aggregates, forming a pressure node plane, were characterised has been applied here to different cell suspensions with increasing order of specificity of cross-linking molecule, i.e. polylysine with chondrocytes; wheat germ agglutinin (WGA) with erythrocytes and surface receptors on neural cells. The outcome of initial cell-cell contact, i.e. whether the cells stuck at the point of contact (collision efficiency = 1) or rolled around each other (collision efficiency = 0), was monitored in situ by video-microscopy. The perimeter fractal dimensions (FD) of 2-D hexagonally symmetric, closely packed aggregates of control erythrocytes and chondrocytes were 1.16 and 1.18, respectively while those for the dendrititc aggregates formed initially by erythrocytes in 0.5microg/ml WGA and chondrocytes in 20 microg/ml polylysine were 1.49 and 1.66. The FDs for control and molecularly cross-linked cells were typical of reaction-limited aggregation (RLA) and transport diffusion-limited aggregation (DLA), respectively. The FDs of the aggregates of cross-linked cells decreased with time to give more closely packed aggregates without clear hexagonal symmetry. Suspensions of neural cells formed dendritic aggregates. Spreading of inter-cellular membrane contact area occurred over 15 min for both erythrocyte and neural cell dendritic aggregates. The potential of the technique to characterise and control the progression of cell adhesion in suspension away from solid substrata is discussed.

Animals↗

The failing Fontan circulation: successful conversion of atriopulmonary connections.

OBJECTIVES: Symptoms from low cardiac output or refractory atrial arrhythmias are complicating atriopulmonary (classical) Fontan connections. We present our experience of converting such patients to total cavopulmonary connections with and without arrhythmia surgery. METHODS: Between 1997 and 2002, 15 patients (mean age, 19.7 +/- 7.0 years) underwent conversion operations 12.7 +/- 3.5 years after atriopulmonary Fontan operations. Preoperative New York Heart Association functional class was I in 2 patients, II in 2 patients, III in 6 patients, and IV in 5 patients. Four patients underwent intracardiac lateral tunnel conversion alone, and 11 received extracardiac total cavopulmonary connection, right atrial reduction, and cryoablation. RESULTS: No mortality occurred. One patient had conduit obstruction in the immediate postoperative period requiring replacement, and another required a redo operation for endocarditis. Average hospitalization was 17.9 +/- 9.38 days; chest drains were removed on median day 4 (range, 1-29; mean, 7.4 +/- 7.58 days). At follow-up (mean, 42.6 +/- 22.1 months), late atrial arrhythmias had recurred in 3 of 4 patients with intracardiac total cavopulmonary connections (without ablation) and 1 of 11 patients with extracardiac total cavopulmonary connections with ablation. All patients are in New York Heart Association class I or II. Exercise ability (Bruce protocol) improved 69% from a mean of 6.18 +/- 4.01 minutes to 10.45 +/- 2.11 minutes (P <.05). Need for antiarrhythmic agents decreased postoperatively (patients receiving < or =1 antiarrhythmic: 9 preoperatively vs 15 at long-term follow-up, P <.05). No patient has required transplantation. Protein-losing enteropathy, which was present in 1 patient, improved transiently with conversion. There was 1 late death from gastrointestinal hemorrhage. CONCLUSIONS: Fontan conversion can be achieved with low mortality and improvement in New York Heart Association class and exercise ability. Concomitant arrhythmia surgery reduces the incidence of late arrhythmias.

Adolescent↗

Manipulation of in vitro toxicant sensors in an ultrasonic standing wave.

Multi-cellular spheroids are increasingly employed as in vitro sensors of toxicants and a single spheroid can be used as a test object. An ultrasonic standing wave trap (USWT) can hold small particles in a medium-flowing system. This study investigated the conditions for holding HepG2 spheroids in an USWT and its relevance to use in toxicity testing. It can take many hours to reach a detectable end point of cell damage in a standard cellular in vitro toxicant assay and the process might be accelerated through increased sample flow past the spheroid. A USWT was employed here to levitate and hold HepG2 spheroids stationary against a flow of 3 mm s(-1) when the acoustic pressure amplitude is 1.9 MPa. The ultrasonic drive frequency was 1.64 MHz. Acoustic microstreaming in the standing wave chamber generated 1 mm s(-1) flow past a levitated spheroid-scale (80 microm diameter) latex particle in the absence of sample through-flow. The conditions required to form aggregates of cells of a HepG2 cell line in a single half wavelength ultrasonic standing wave mini-chambers are also described here. It is argued that the manipulation capabilities demonstrated may have potential in increasing the efficiency of in vitro toxicant detection by spheroids. Preliminary, visual (unquantified) fluorescence microscopy observations of spheroids levitated in the standing wave in the presence of the toxicant DL-propranolol do suggest accelerated loss of viability compared with controls.

Biosensing Techniques↗