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Biomedical subjects

S Myint

Publications and source records attributed to S Myint.

At least 19 recordsLinked to original sources
PubMed2002

Effects of rhinovirus-induced common colds on granulocyte activity in allergic rhinitis.

OBJECTIVE: To explore the activities of mast cells, eosinophils, and neutrophils in patients with allergic rhinitis developing common colds and increased responsiveness to allergen following nasal rhinovirus inoculation. METHODS: We have revisited a nasal lavage material obtained from 17 patients who were successfully inoculated with rhinovirus outside the pollen season and received nasal allergen challenges before and after inoculation. We have examined indices of mast cell activity (tryptase), eosinophil degranulation (eosinophil peroxidase; EPO), and neutrophil activation (myeloperoxidase; MPO). RESULTS: Allergen challenges performed before rhinovirus inoculation increased the nasal output of EPO. Notably, this response was significantly greater after rhinovirus inoculation (cf. before inoculation). The output of MPO was also increased following allergen challenge after, but not before, rhinovirus inoculation. Nasal lavage fluid levels of tryptase were increased following allergen challenge similarly before and after rhinovirus inoculation. Also, the viral infection did not affect the baseline levels of tryptase. CONCLUSIONS: The present data demonstrate that rhinovirus infections activate both eosinophils and neutrophils, but that they may not affect mast cell activity. We suggest that common colds in part through stimulation of granulocyte activity potentiate the airway inflammation in allergic diseases.

Administration, Intranasal↗
PubMed2001

Prospective study of the incidence, aetiology and outcome of adult lower respiratory tract illness in the community.

BACKGROUND: Acute lower respiratory tract illness in previously well adults is usually labelled as acute bronchitis and treated with antibiotics without establishing the aetiology. Viral infection is thought to be the cause in most cases. We have investigated the incidence, aetiology, and outcome of this condition. METHODS: Previously well adults from a stable suburban population consulting over one year with a lower respiratory tract illness were studied. For the first six months detailed investigations identified predetermined direct and indirect markers of infection. Evidence of infection was assessed in relation to presenting clinical features, indirect markers of infection, antibiotic use, and outcome. RESULTS: Consultations were very common, particularly in younger women (70/1000 per year in previously well women aged 16-39 years), mainly in the winter months; 638 patients consulted, of whom 316 were investigated. Pathogens were identified in 173 (55%) cases: bacteria in 82 (Streptococcus pneumoniae 54, Haemophilus influenzae 31, Moraxella catarrhalis 7), atypical organisms in 75 (Chlamydia pneumoniae 55, Mycoplasma pneumoniae 23), and viruses in 61 (influenza 23). Seventy nine (24%) had indirect evidence of infection. Bacterial and atypical infection correlated with changes in the chest radiograph and high levels of C reactive protein but not with (a) the GP's clinical assessment of whether infection was present, (b) clinical features other than focal chest signs, and (c) outcome, whether or not appropriate antibiotics were prescribed. CONCLUSIONS: Over 50% of patients have direct and/or indirect evidence of infection, most commonly bacterial and atypical pathogens, but the outcome is unrelated to the identified pathogens. Many patients improve without antibiotics and investigations do not help in the management of these patients. GPs can reassure patients of the causes and usual outcome of this self-limiting condition.

Acute Disease↗
PubMed2001

A model of viral wheeze in nonasthmatic adults: symptoms and physiology.

Episodic wheezing associated with viral infections of the upper respiratory tract (URT) is a common problem in young children but also occurs in adults. It is hypothesized that an experimental infection with human coronavirus (HCoV), the second most prevalent common cold virus, would cause lower respiratory tract (LRT) changes in adults with a history of viral wheeze. Twenty-four viral wheezers (15 atopic) and 19 controls (seven atopic) were inoculated with HCoV 229E and monitored for the development of symptoms, changes in airway physiology and provocative concentration of methacholine causing a 20% fall in forced expiratory volume in one second (FEV1) (PC20). At baseline, viral wheezers were similar to controls in PC20 (mean+/-SD log2PC20: 5.1+/-1.9 and 5.8+/-1.4 g x L(-1), respectively) but had a lower FEV1 than controls (mean+/-SD 85.8+/-11.4 and 95.6+/-13.2% predicted, respectively p < 0.05). Nineteen viral wheezers and 11 controls developed colds. Viral wheezers with colds reported significantly more URT symptoms than controls (median scores (interquartile range): 24 (10-37) and 6 (4-15), respectively p = 0.014). Sixteen viral wheezers and no controls reported LRT symptoms (wheeze, chest tightness and shortness of breath). The viral wheezers with colds had small (3-4%) reductions in FEV1 and peak expiratory flow on days with LRT symptoms (days 3-6), but a progressive reduction in PC20 from baseline on days 2, 4 and 17 after inoculation (by 0.82, 1.35 and 1.82 doubling concentrations, respectively). The fall in PC20 affected both atopic and nonatopic subjects equally. There were no changes in FEV1 or PC20 in controls. An adult model of viral wheeze that is independent of atopy and therefore, of classical atopic asthma was established.

Adult↗
PubMed1999

Experimental common cold increases mucosal output of eotaxin in atopic individuals.

BACKGROUND: In view of recent observations demonstrating that rhinovirus infections are associated with increased local activity of eosinophils, we hypothesized that eotaxin, a selective eosinophil chemoattractant, may be involved in eosinophil recruitment/activation in common cold infections. METHODS: Twenty-three patients with seasonal allergic rhinitis were inoculated with human rhinovirus 16 (HRV 16) outside the pollen season. Sequential diluent and allergen (10(3) SQ-U) challenges, each followed by nasal lavage, were carried out about 3 months before and 4 days after virus inoculation. RESULTS: Seventeen patients developed common cold and were further analyzed. Lavage fluid levels of eotaxin were increased at the height of active common cold (day 4 after inoculation) both at baseline (after diluent challenge) (P<0.01) and acutely after allergen challenge (P<0.05). CONCLUSIONS: Common cold symptoms after nasal HRV 16 inoculation are associated with increased nasal mucosal output of eotaxin, suggesting that this chemokine is partly responsible for recruitment/activation of airway mucosal eosinophils in common cold infections.

Blood Proteins↗
PubMed1999

Allergen challenge-induced acute exudation of IL-8, ECP and alpha2-macroglobulin in human rhinovirus-induced common colds.

Rhinovirus infections cause exacerbations of eosinophilic airway disease. The acute effects of allergen-challenge on nasal interleukin-8 (IL-8), eosinophil cationic protein (ECP), and alpha2-macroglobulin were examined in atopic subjects with common cold symptoms. Twenty-three patients with seasonal allergic rhinitis were inoculated with human rhinovirus 16 outside the pollen season. Diluent and allergen challenges, followed by nasal lavages, were carried out about 3 months before and 4 days after virus inoculation. Seventeen patients developed significant common cold symptoms with increased nasal lavage fluid levels of alpha2-macroglobulin, IL-8, and ECP at baseline (p<0.001-0.05 versus before inoculation), and were further increased by allergen challenge (p< 0.001-0.05); IL-8 and ECP levels were correlated (r = 0.63, p<0.001). Before inoculation, the six patients who later did not develop common cold symptoms had high levels of IL-8 and myeloperoxidase (MPO), and exhibited strong allergen-induced plasma exudation responses (alpha2-macroglobulin). After inoculation, IL-8 and ECP did not increase in these symptomless subjects. In conclusion, high nasal interleukin-8 and myeloperoxidase levels and exudative hyperresponsiveness may protect against infection. The association between nasal interleukin-8 and eosinophil cationic protein in common cold, particularly that observed in nasal lavage fluids after allergen-induced acute exudation of plasma, suggests the involvement of interleukin-8 in exacerbation of airway mucosal eosinophil activity.

Adolescent↗
PubMed1998

Dome osteotomy with T-plate fixation for cubitus varus deformity in an adult patient.

Cubitus varus (gun stock deformity) is the most common long-term complication resulting from a malunion of a supracondylar fracture of the humerus in children. The reported series of complication varies from 9 to 58%. There are many published papers describing corrective supracondylar osteotomy mainly for children. We describe a method of performing supracondylar osteotomy that produced a very satisfactory result in an adult patient.

Adult↗
PubMed1997

Prospective case-control study of role of infection in patients who reconsult after initial antibiotic treatment for lower respiratory tract infection in primary care.

OBJECTIVE: To assess direct and indirect evidence of active infection which may benefit from further antibiotics in adults who reconsult within 4 weeks of initial antibiotic management of acute lower respiratory tract infection in primary care. DESIGN: Observational study with a nested case-control group. SETTING: Two suburban general practices in Arnold, Nottingham, over 7 winter months. SUBJECTS: 367 adults aged 16 years and over fulfilling a definition of lower respiratory tract infection and treated with antibiotics. 74 (20%) patients who reconsulted within 4 weeks for the same symptoms and 82 "control" patients who did not were investigated in detail at fallow up. MAIN OUTCOME MEASURES: Direct and indirect evidence of active infection at the time of the reconsultation or the follow up visit with the research nurse for the controls. Investigations performed included sputum culture, pneumococcal antigen detection, serial serology for viral and atypical pathogens and C reactive protein, throat swabs for detecting viral and atypical pathogens by culture and polymerase chain reaction, and chest radiographs. RESULTS: Demographic and clinical features of the groups were similar. Two thirds of the 74 patients who reconsulted received another antibiotic because the general practitioner suspected continuing infection. Any evidence of infection warranting antibiotic treatment was uncommon at reconsultation. The findings for the two groups were similar for the occurrence of identified pathogens; chest x ray changes of infection (present in 13%); and C reactive protein concentrations, which had nearly all fallen towards normal. Only three patients in the reconsultation group had concentrations > or = 40 mg/l. Pathogens identified at follow up in the 156 patients in both groups included ampicillin sensitive bacteria in six. Atypical infections diagnosed in 27 (Chlamydia pneumoniae in 22) and viral infections in 54 had probably been present at the initial presentation. CONCLUSION: Our study suggests that active infection, which may benefit from further antibiotics, is uncommon in patients who reconsult after a lower respiratory tract infection, and a repeat antibiotic prescription should be the exception rather than the rule. Other factors, such as patients' perception of their illness, may be more important than disease and infection in their decision to reconsult.

Adolescent↗
PubMed1997

Sequence variation in the early genes E1E4, E6 and E7 of human papilloma virus type 6.

The majority of condylomata acuminata (anogenital warts) are caused by infection with Human Papilloma Virus type 6 (HPV-6). We have sequenced the HPV-6 early genes, E1-E4, E6 and E7 from wart biopsy DNA samples sourced from the UK and USA and derived a consensus sequence for these genes and the proteins they encode. When compared to the prototype HPV-6b sequence, published over 12 years ago, the E1-E4 consensus sequence showed 3/91 (3.3%) amino acid changes, the E6 consensus sequence showed 1/150 (0.7%) changes and the E7 consensus sequence showed 1/98 (1.0%) changes. Since many of the early gene sequences from biopsy material were more similar to the HPV-6a subtype than HPV-6b, this data supports the use of HPV-6a as the HPV-6 prototype.

Condylomata Acuminata↗
PubMed1997

The incidence and detection of HPV in the upper aerodigestive tract using brush and biopsy techniques.

The association between human papillomavirus (HPV) and squamous carcinoma is well established. In the polymerase chain reaction (PCR) we have an effective technique for detecting small quantities of viral DNA, but the assay requires tissue taken at endoscopy to reveal the presence or absence of HPV. Brushings have been used effectively elsewhere in the body to obtain cytological material. This study set out to ascertain if sufficient viral DNA could be obtained, using a laryngeal brushing and the PCR, to detect the presence or absence of HPV. Six patients with squamous carcinoma of the larynx and seven controls who were having laryngoscopy for other reasons underwent laryngeal biopsy. In addition, in the patients with carcinoma, biopsies were taken at the tumour margins and brushings from both sites. The samples were tested for the presence of HPV types 6, 11, 16, 18 and 31 by means of the PCR. The distribution of HPV types was as expected in the biopsy specimens, but only one brushing detected any HPV type at all. We conclude that laryngeal brushing is an inadequate technique for assessing the presence of HPV in the larynx.

Adolescent↗
PubMed1997

The presence of free infectious cytomegalovirus (CMV) in the plasma of donated CMV-seropositive blood and platelets.

An in vitro study was carried out to determine the presence of free infectious CMV in the supernatant of donated units of blood and platelets which were known to be CMV seropositive. One sample was taken from each of 10 units of CMV-seropositive platelet donations which were 4 days old. Ten units of seropositive blood were sampled at intervals over their storage lifespan. Each sample was divided into two and thrombin was added to one of them. The samples were all prepared by centrifugation. The resulting supernatant from the clotted samples was used in in vitro culture studies using the MRC-5 cell line to ascertain the infectivity of the samples. The anticoagulated supernatants were subjected to PCR analysis to detect the presence of free genomic CMV DNA. All of the units of blood and platelets tested positive for the presence of genomic CMV DNA by PCR. Seven out of the 10 units of blood were culture positive from samples taken 3-4 weeks into their shelf-life. None of the platelet samples was culture positive. The cultures of supernatants taken from seropositive blood were negative when the units were fresh, but further into their storage life, the cultures became positive, indicating that infectious material was released into the supernatant during storage, presumably due to the breakdown of intact white cells.

Blood Donors↗
PubMed1996

Gas chromatographic determination of eugenol in ethanol extract of cloves.

An ethanolic extract of cloves was analyzed by gas chromatography directly to identify eugenol and other major phenolic compounds without previous separation of other components. Separation was performed on a fused-silica capillary column of 30 m x 0.53 mm I.D., 0.53 microns film thickness. The detector was a flame ionization detector. Helium gas at a flow-rate of 3 ml/min was used as a carrier gas. The analysis were performed with linear temperature programming. Nine components were detected and special attention was given to the major phenolic compound, eugenol.

Chromatography, Gas↗
PubMed1995

Biphasic synovial sarcoma in the small intestinal mesentery.

BACKGROUND: A 46-year-old man presented with recurrent anemia and polyarthralgia. Investigations revealed a mass in the ileal mesentery, which was resected. Results of routine histologic examination suggested a diagnosis of synovial sarcoma, a rare malignancy usually not reported at this site. METHODS: Tissue was examined immunohistochemically, ultrastructurally, and by fluorescent in situ hybridization to confirm the diagnosis. RESULTS: Immunohistochemical studies revealed widespread labeling for cytokeratins and focal labeling for desmin and vimentin in the epithelial component, with labeling for epithelial membrane antigen in the epithelial and spindle-cell components. Fluorescent in situ hybridization analysis showed the characteristic t(X;18) translocation of synovial sarcoma. CONCLUSIONS: This is a unique case of synovial sarcoma in the small intestinal mesentery. Immunohistochemical labeling confirmed the diagnosis, although, to the authors' knowledge, the pattern of desmin labeling has not been described previously. The clinical association with polyarthralgia, which resolved after removal of the neoplasm, also has not been described previously.

Desmin↗
PubMed1995

Viral contamination of environmental surfaces on a general paediatric ward and playroom in a major referral centre in Riyadh.

In order to determine the incidence of viral contamination of environmental surfaces in a hospital in Saudi Arabia. A 6-month prospective study was carried out on a general paediatric ward in which both enteric and respiratory viruses were screened. Weekly samples were taken between August 1993-February 1994. A total of 155 samples were taken in which 11 (7%) tested positive for rotavirus. No other viruses were detected. Internal and external temperatures were monitored and an increase in rotavirus incidence was noted with decrease in temperature. Rotavirus was detected on surfaces involving human activity (toilet handles, televisions, toys and vital signs chart). One patient had rotavirus on his hands but no staff were found to carry rotavirus. Further contamination of environmental surfaces (9%) was detected during an increased incidence of rotavirus infection. A proper programme of disinfection and handwashing is essential in order to eliminate this mode of transmission.

Child↗
PubMed1995

Astroviruses.

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Adult↗