Search PubMed⌕ Search

Biomedical subjects

S Rogers

Publications and source records attributed to S Rogers.

At least 37 records · Page 2Linked to original sources

Application of 16S rDNA-DGGE to examine the microbial ecology associated with a social wasp Vespula germanica.

Invertebrates host numerous bacteria, with interactions ranging from pathogenesis to symbiosis. While certain symbiotic relationships have been well studied, little is known about the dynamics of these bacterial communities. Denaturing gradient gel electrophoresis (DGGE) was used to examine the bacterial microflora associated with the eusocial wasp Vespula germanica. DGGE profiles of larval guts revealed a variable microflora, suggesting that V. germanica is not dependent on a particular suite of mutualists. The variation in profiles was not related to season, nest size or macrohabitat. Sequences corresponding to Lactococcus, Lactobacillus, a novel Leuconostoc and two Rickettsiella grylli strains were obtained. DGGE proved to be a useful technique for characterizing the wasp microflora. Given the importance of microbial communities to invertebrates, there is much to be gained from the application of such techniques.

Animals↗

GLUT12 expression in human placenta in first trimester and term.

The aim of this study was to characterize the expression of a novel glucose transporter protein GLUT12 in human placenta. GLUT12 mRNA expression was identified by RT-PCR in extracts from five normal term placentae and in extracts from cultured cells of the JAR, JEG-3 and HTR-8Svneo cell lines. In further studies, paraffin sections of first trimester tissue from chorionic villus sampling and term tissue obtained after delivery were analysed by immunohistology with a GLUT12 specific polyclonal antibody. GLUT12 immunoreactivity was expressed predominantly in the syncytiotrophoblast and in extra-villous trophoblast cells in first trimester tissues at 10, 11 and 12 weeks' gestation. In term tissue, however, GLUT12 staining was not detected in syncytiotrophoblast and was found predominantly in villous vascular smooth muscle cells and villous stromal cells. These results suggest that there is a dynamic spatial and temporal expression pattern for the novel glucose transporter GLUT12 in human placenta.

Adult↗

Fear of recurrence and possible cases of anxiety and depression in orofacial cancer patients.

Recurrence risk in orofacial cancer patients is relatively high in comparison to other cancers. Little information exists on whether patients are unduly concerned over the possibility of recurrence and the association of this concern with psychological morbidity. Aim of study was to assess fear of recurrence and psychological morbidity in orofacial cancer patients. Two samples of patients with orofacial cancer were followed prospectively. First sample (n = 87) were consecutively drawn 3 months and 7 months following initial treatment. Second sample (n = 100) were cross-sectionally drawn from out-patient list and followed 2 years later. A single question item was employed to assess fear of recurrence used in previous work. Hospital Anxiety and Depression Scale was adopted as the measure of psychological morbidity. A prospective survey design was employed. Over 80% of patients expressed concern over the possibility of recurrence at 3 months post treatment. This level reduced to 72% at 7 months (P=0.06). Approximately two-thirds of patients sampled cross-sectionally were concerned at both assessment occasions. Psychological morbidity was greatest at 3 months post treatment (possible cases: anxiety 37% and depression 28%). Women were more likely to report anxiety (at possible case level) than men 3 months following treatment (P<0.05). Patients aged 65 or more years were less concerned about recurrence. This effect was significant on both occasions that sample two patients were assessed (P's<0.002). Very few patients who expressed no concern about recurrence, at 3 months, were found to report anxiety or depression sufficient to be recognized as a possible case (3 and 0% respectively). The positive association between psychological morbidity and fears of recurrence was significant at the majority of data collection points, with the exception that depression was more independent of these concerns.

Age Factors↗

Guidelines for dosimetry and calibration in ultraviolet radiation therapy: a report of a British Photodermatology Group workshop.

This report examines the dosimetry of ultraviolet (UV) radiation applied to dermatological treatments, and considers the definition of the radiation quantities and their measurement. Guidelines are offered for preferred measurement techniques and standard methods of dosimetry. The recommendations have been graded according to the American Joint Committee on Cancer classification of strength of recommendation and quality of evidence (summarized in Appendix 5).

Humans↗

Adverse effects with long-term cyclosporin for severe psoriasis.

The use of cyclosporin A (CSA) for the treatment of severe psoriasis is well established. However its use is limited by its adverse effects, especially nephrotoxicity. We reviewed 28 patients treated with CSA for severe psoriasis over an 11-year period. All patients were on long-term CSA treatment (median duration 55.5 months). Twenty patients developed renal impairment which required discontinuation of treatment in seven. Twelve patients' renal function stabilized on dose reduction and one improved. Sixteen patients developed hypertension. For this small group of patients with severe psoriasis, recalcitrant to other treatments, CSA afforded better quality of life which they otherwise could not enjoy. Although this comes at a cost with the development of renal impairment we feel that such patients can be continued on CSA provided that they are under the combined care of a dermatologist and a nephrologist.

Acute Kidney Injury↗

Bone loss associated with the use of LHRH agonists in prostate cancer.

Hypogonadism is a recognised cause of osteoporosis in men. When patients with advanced prostate cancer are treated with luteinising hormone releasing hormone (LHRH) agonist analogues their circulating testosterone levels decline and these patients may develop fractures.We have undertaken a cross-sectional study on a cohort of patients treated with goserelin (n=41) and compared their bone density and bone turnover with patients with prostate cancer not on goserelin and elderly patients living in the community.There was no difference in bone density between the patients on treatment and those living in the community and there was a similar incidence of osteoporosis (50 and 42%, respectively). The bone marker measurements were higher in the treated patients: urine N-telopeptide (NTX) 80.1 (9) (mean (s.e.)) BCE/mmol, compared to 30.1 (2.9), P<0.001 in elderly patients; and bone alkaline phosphatase 41.9 (6.1) u/l in treated patients and 20.7 (1.5) in untreated prostate cancer patients, P<0.002. Patients on treatment with radionuclide scan evidence of metastases did not have higher bone marker values than those with negative scans.As increased bone turnover and low bone density are associated with enhanced risk of osteoporotic fractures, we suggest that patients on LHRH agonist analogues should receive advice and possibly anti-bone resorptive treatment with bisphosphonates to prevent further bone loss and fractures.Prostate Cancer and Prostatic Diseases (2001) 4, 161-166.

Journal Article↗

Atypical presentation of Acanthamoeba keratitis.

PURPOSE: To present two cases of minimal pain Acanthamoeba keratitis to alert clinicians to remember Acanthamoeba when evaluating atypical cases of keratitis. METHODS: The histories of two cases were reviewed with attention to clinical presentation subjective complaints, treatment, and long-term outcome. RESULTS: In case 1, a 24-year-old man presented with decreased vision and an irritated feeling in his eye. He did not wear contact lenses. His initial diagnosis was adenoviral conjunctivitis. One month later, he was diagnosed with atypical herpes simplex keratitis and started on acyclovir. Two weeks later, he was referred to the Cornea Service. Further history revealed the patient to be a professional triathlete who trained by swimming in a fresh water pond. He was found to have an unusually high pain tolerance. Biopsy revealed Acanthamoeba. He was admitted for intensive therapy with neomycin, propamidine isethionate, and polyhexamethylene biguanide. Two years after diagnosis, he has best-corrected visual acuity of 20/100. In case 2, a 28-year-old man with known herpes simplex keratitis presented with decreased vision. He was started on topical trifluridine. After 6 weeks without improvement, he was referred for corneal evaluation. His eye always remained comfortable. Corneal sensation was markedly decreased. Further history revealed that he swam in fresh water. Biopsy was positive for Acanthamoeba. After 1 year of therapy with polyhexamethylene biguanide and neomycin, visual acuity was 20/200, and the patient underwent a corneal transplant. CONCLUSION: Acanthamoeba keratitis must be considered in the differential diagnosis of keratitis, even without the classic presentation of severe pain and predisposing corneal trauma, including contact lens wear.

Acanthamoeba↗

Bacteriophage K1-5 encodes two different tail fiber proteins, allowing it to infect and replicate on both K1 and K5 strains of Escherichia coli.

A virulent double-stranded DNA bacteriophage, Phi K1-5, has been isolated and found to be capable of infecting Escherichia coli strains that possess either the K1 or the K5 polysaccharide capsule. Electron micrographs show that the virion consists of a small icosohedral head with short tail spikes, similar to members of the Podoviridae family. DNA sequence analysis of the region encoding the tail fiber protein showed two open reading frames encoding previously characterized hydrolytic phage tail fiber proteins. The first is the K5 lyase protein gene of Phi K5, which allows this phage to specifically infect K5 E. coli strains. A second open reading frame encodes a protein almost identical in amino acid sequence to the N-acetylneuraminidase (endosialidase) protein of Phi K1E, which allows this phage to specifically infect K1 strains of E. coli. We provide experimental evidence that mature phage particles contain both tail fiber proteins, and mutational analysis indicates that each protein can be independently inactivated. A comparison of the tail gene regions of Phi K5, Phi K1E, and Phi K1-5 shows that the genes are arranged in a modular or cassette configuration and suggests that this family of phages can broaden host range by horizontal gene transfer.

Antigens, Bacterial↗

An unusual presentation of cat-scratch disease.

Cat-scratch disease (CSD) is a relatively common entity, particularly in children. The most common sites of involvement are the axillary lymph nodes, followed by cervical, pre-auricular and submandibular lymph nodes. We present a case of cat-scratch disease in which the initial clinical features were indistinguishable from those of acute bacterial tonsillitis with jugulodigastric lymphadenopathy. This previously unreported apparent mode of presentation is discussed with reference to the current understanding of the disease.

Acute Disease↗

Recovering maxillofacial trauma patients: the hidden problems.

This longitudinal study highlights the psychological and functional problems that can result from maxillofacial trauma. This is the first study to report outcome at one year. A total of 147 patients admitted for surgery following facial trauma were recruited over a seven-month period. Three questionnaires were used to record patient-derived levels of dysfunction: the Hospital Anxiety Depression scale, a modified University of Washington Quality of Life questionnaire and five non-validated facial trauma items. At one year 46 patients (31%) responded. Although there were significant improvements in scores from pre-operatively to one year, with all patients being discharged from outpatient follow-up, there was a substantial level of subjective symptomatology. Most notable was the level of anxiety and depression, which were present in 30% of the sample at both time points. Health-care professionals tend to underestimate the long-term effects of maxillofacial trauma. To improve patient care, greater appreciation of these problems is required at the time of initial management.

Adaptation, Psychological↗

Comparison of fever treatments in the critically ill: a pilot study.

BACKGROUND: Fever in critically ill patients is often treated with antipyretics or physical cooling methods. Although fever is a host defense response that may benefit some critically ill patients, others may not tolerate the cardiovascular demands associated with fever. OBJECTIVES: To compare antipyretics and physical cooling for their effects on core body temperature and cardiovascular responses in critically ill patients. METHODS: The antipyretic administered was 650 mg of acetaminophen. Physical cooling was accomplished by anterior placement of a cooling blanket at 18 degrees C. Core temperature and cardiovascular responses were measured in 14 febrile (body temperature, 38.8 degrees C) critically ill patients at baseline before treatment and up to 3 hours after treatment. Patients able to receive acetaminophen were randomly assigned to receive either acetaminophen only (n = 5) or acetaminophen in combination with a cooling blanket (n = 3). Patients not able to receive acetaminophen were treated with physical cooling only (n = 6). RESULTS: Mean body temperature decreased minimally from baseline to 3 hours after treatment in the physical-cooling-only group (from 39.1 degrees C to 39.0 degrees C) and in the physical cooling and acetaminophen group (from 39.1 degrees C to 38.6 degrees C), but the mean body temperature increased in the acetaminophen-only group (from 39.2 degrees C to 39.4 degrees C). Other notable findings included a slight increase in systemic vascular resistance index in the physical-cooling-only group and in the physical-cooling-plus-acetaminophen group. CONCLUSIONS: Although the study included only 14 subjects, the findings will provide information for future studies in febrile critically ill patients.

Acetaminophen↗

The barriers to effective management of heart failure in general practice.

BACKGROUND: Several studies have shown that most patients with heart failure are not investigated and treated according to published guidelines. More effective management could reduce both mortality and morbidity from heart failure. AIM: To identify the reasons for gaps between recommended and actual management of heart failure in general practice. DESIGN OF STUDY: A nominal group technique was used to elicit general practitioners' (GPs') perceptions of the reasons for differences between observed and recommended practice. SETTING: Ten Medical Research Council General Practice Framework practices in the North Thames region. METHOD: Data were collected on the investigation and treatment of heart failure in the 10 participating practices and presented to 49 GPs and 10 practice nurses from those practices. RESULTS: Of the 674 patients requiring echocardiograms, 226 were referred for echocardiography (34%), and 183/391 (47%) with probable heart failure were prescribed angiotensin-converting enzyme inhibitors. A wide variety of barriers were elicited. The main barrier to the use of echocardiograms in the diagnosis of heart failure was lack of open access. The main barrier to the use of angiotensin-converting enzyme inhibitors in treating heart failure was GPs' concerns about their possible adverse effects. CONCLUSION: The barriers to the effective management of heart failure in general practice are complex. We recommend further research to establish whether multifaceted intervention programmes based on our findings can improve the management of heart failure in primary care.

Aged↗

Identification of spores in the polycentric anaerobic gut fungi which enhance their ability to survive.

Two new isolates of the gut fungi were obtained from the rumen digesta and faeces of a cow. These isolates, designated Anaeromyces following rDNA typing, displayed a polycentric growth habit but differed from all other gut fungi in that they were able to survive in the laboratory for considerable periods without the need for sub-culture. Light microscopy of preparations from old liquid-grown cultures revealed the presence of DNA-containing spores with two or four chambers. A comparative evaluation of the growth produced when fresh media were inoculated with a sample originating from young or old cultures revealed that active growth was delayed with the inoculum from the older culture. We propose that the chambered spores observed in these cultures provide an alternative path in the life cycle of these fungi and may function as a resting stage within the anaerobic environment of the herbivore gut.

Journal Article↗

Antioxidant capacity and oxygen radical diseases in the preterm newborn.

BACKGROUND: Bronchopulmonary dysplasia, intraventricular hemorrhage, necrotizing enterocolitis, and retinopathy of prematurity may be different manifestations of oxygen radical diseases of prematurity (ORDP). OBJECTIVE: To test the hypothesis that the antioxidant capacity of cord blood serum will predict risk of ORDP. DESIGN: An inception cohort of premature neonates was followed up from birth until discharge or death to determine if outcome was related to cord blood serum antioxidant capacity, as determined by a manual assay measuring the relative inhibition of oxidation of 2,2'-azino-di-(3-ethylbenzthiazoline)-6 sulfonic acid (ABTS). Possible correlations between antioxidant capacity and various perinatal factors were also tested. SETTING: Level 3 newborn intensive care unit. PATIENTS: All inborn very low-birth-weight neonates from whom cord blood was available and for whom maternal consent was obtained were included. Newborns who died in the first week of life or who had major congenital malformations were excluded. A convenience sample of newborns weighing more than 1500 g was used to perfect assay and explore confounders. MAIN OUTCOME MEASURES: Significant ORDP was defined as the presence of intraventricular hemorrhage greater than grade 2, retinopathy of prematurity greater than stage 1, bronchopulmonary dysplasia at the postconceptional age of 36 weeks, or necrotizing enterocolitis with the hypothesis that neonates with ORDP will have lower antioxidant capacity in cord blood serum. RESULTS: Serum antioxidant capacity at birth correlated with gestational age for the entire sample of 41 neonates and for the 26 neonates born before 32 weeks' gestation. After correction for gestational age, cord serum antioxidant capacity did not correlate with maternal smoking, preeclampsia, chorioamnionitis, cord pH Apgar scores, or any of the ORDP studied. CONCLUSION: Cord serum antioxidant capacity correlates with gestational age but does not predict ORDP risk.

Antioxidants↗

Influence of complete spinal cord injury on skeletal muscle mechanics within the first 6 months of injury.

In this study we examined the influence of complete spinal cord injury (SCI) on the mechanical characteristics of skeletal muscle in vivo within 6 months of the injury. Surface electrical stimulation (ES) was applied to the left m. quadriceps femoris of patients at 6, 11 and 24 weeks after injury. Surface ES was also applied to seven able-bodied controls (AB) at two time points 18 weeks apart. ES consisted of 2 bouts of 20, 1-s isometric contractions with 2 s and 2 min of rest between contractions and bouts, respectively. The time from 20-80% of peak torque (rise time) and the half relaxation time (1/2 RT) were determined for the first and for the last few contractions. Force loss over repeat contractions was greater in SCI than AB (27% vs 95%; P = 0.0001), and did not change over the 18-week period. Rise time did not change over repeat contractions, was not different between groups, and nor did it change over the 18-week period (range: 150-172 ms). 1/2 RT showed several group differences. Overall, 1/2 RT was longer at the beginning of ES in SCI than AB [mean (SE) 133 (15) ms vs 90 (6) ms, P = 0.037]. Slowing of relaxation time with force loss over repeat contractions was found in SCI at 24 weeks after injury [167 (18) ms, P = 0.016], but not at 6 [128 (14) ms] or 11 [145 (12) ms] weeks after injury. AB, in contrast, showed prolonged relaxation times, with force loss at both time points [115 (10) ms and 113 (11) ms; P = 0.0001]. The results indicate that SCI alters the relaxation but not contractile properties of mixed skeletal muscle within the first 24 weeks of injury. Altered calcium handling and contraction-induced fiber injury are suggested to explain the slower relaxation time per se, and the prolonged relaxation with force loss observed after SCI.

Adolescent↗

Laparoscopic radiofrequency ablation of primary and metastatic liver tumors. Technical considerations.

BACKGROUND: Radiofrequency thermal ablation is a new technology for the local destruction of liver tumors. Since we first described laparoscopic radiofrequency ablation (LRFA) for the treatment of liver tumors, much has been learned about patient selection, laparoscopic ultrasound (LU) guided placement of the ablation catheter, monitoring of the ablation process, and patient follow-up. METHODS: Since January 1996 we have performed LRFA of 250 tumors in 67 patients including 85 adenocarcinomas, 107 neuroendocrine tumors, 34 sarcomas, 1 melanoma, and 11 hepatomas. We used LU to guide placement of the ablation catheter and to monitor the ablation process. Most of the patients had two trocars (camera and laparoscopic ultrasound) with the 15-gauge ablation catheter (RITA Medical Systems, Mountain View, CA, USA) placed percutaneously. RESULTS: The LRFA procedure was completed successfully in all patients, with 1 to 14 lesions per patient, ranging in size from 0.5 to 10 cm in diameter. The entire liver could be examined by LU via right subcostal ports. Criteria for successful ablation were 5-min ablation times at 100 degrees C with 1-min cool-down temperatures of 60 degrees to 70 degrees C. Outgassing of dissolved nitrogen, monitored by ultrasound, was useful in confirming the zone of ablation. Intralesional color-flow Doppler, seen before ablation, was eliminated after ablation. Placement of the grounding pad closer to the lesion on the back rather than the thigh resulted in more efficient energy delivery to the tumor. Lesions larger than 3 cm in diameter required overlapping ablations to achieve a 1-cm margin of normal liver. Most patients required overnight hospitalization, with no coagulopathy or electrolyte disturbances noted. CONCLUSIONS: The LRFA procedure is a novel, minimally invasive technique for treatment of liver tumors that have failed conventional therapy. This study documents the technical aspects of targeting lesions and performing reproducible zones of ablation. Familiarity with these techniques should lead to more widespread application.

Adenocarcinoma↗