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M V Martin

Publications and source records attributed to M V Martin.

159 records · Page 9Linked to original sources
PubMed1979

Germ-tube formation by oral strains of Candida tropicalis.

Candida species isolated from the mouths of healthy children and of patients with denture stomatitis included strains of Candida tropicalis that formed germ tubes when incubated in serum. Twenty-six germ-tube-forming strains of C. albicans and of C. tropicalis were subcultured weekly for 9 wk on blood agar and on Sabouraud's agar and the ability of each subculture to form germ tubes was measured. All the strains of C. albicans formed almost as many germ tubes after nine weekly subcultures as they did when first isolated. By contrast, although all 26 strains of C. tropicalis formed germ tubes when first isolated, all had lost the ability to do so after six serial weekly subcultures. Germ-tube formation should not be the sole criterion for the identification of oral C. albicans strains.

Adult↗
PubMedDate not supplied

Rings and watches: should they be removed prior to operative dental procedures?

OBJECTIVES: There is no clear evidence to support the recommendation that rings and watches should be removed prior to operative dental procedures. The aim of this study was to measure and identify the bacteria isolated from the skin under rings and watches worn by a group of dental surgeons and to compare the results with a group of non-clinical staff. METHODS: Forty volunteers participated in the study; of these 20 were dental surgeons and 20 were non-clinical staff. Four skin sites were sampled for each volunteer; the skin directly under the ring and on the same finger of the other hand and the skin under the watch face and wrist of the control hand. Bacteria on the swabs were dispersed and inoculated onto plates, which were incubated aerobically for 24 h at 37 degrees C. RESULTS: In both groups of volunteers there was a significantly greater number of bacteria isolated from under rings and watches compared with control sites. Few qualitative differences were found between the microflora found on the skin under rings and watches in the two volunteer groups. CONCLUSIONS: The bacterial flora isolated from volunteers do not commonly cause oral infections but could pose a threat to the immunocompromised patient, particularly in the event of gloves becoming torn or perforated. Effective hand disinfection is difficult to achieve if ring and watches are not removed; they should therefore be removed prior to hand disinfection and donning of gloves.

Bacteria↗
PubMedDate not supplied

The protein content of dental rubber dams.

OBJECTIVES: The purpose of this study was to analyse the protein content of 17 commonly used rubber dams and to determine if they contained known allergenic proteins. METHODS: Proteins were eluted with buffer from 17 brands of commercially available rubber dams. The quantity of eluted protein was measured and expressed in micrograms in every gram of rubber. The molecular weights of the individual proteins eluted were then measured after resolution on sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE) and compared with those of known allergens. RESULTS: The rubber dams were shown to contain significant amounts of protein (950-5850 micrograms). The subsequent analysis of these proteins using SDS-PAGE confirmed that some of these proteins were of the same molecular weight as known allergens. CONCLUSIONS: The results of this study confirm that all the rubber dams tested contained significant amounts of protein. The molecular weights of these proteins correspond with those of known allergens, and they could, therefore, be a cause of hypersensitivity reactions to dental rubber dams.

Allergens↗
PubMedDate not supplied

Reaction of cytochrome P450 with cumene hydroperoxide: ESR spin-trapping evidence for the homolytic scission of the peroxide O-O bond by ferric cytochrome P450 1A2.

ESR spin trapping was used to investigate the reaction of rabbit cytochrome P450 (P450) 1A2 with cumene hydroperoxide. Cumene hydroperoxide-derived peroxyl, alkoxyl, and carbon-centered radicals were formed and trapped during the reaction. The relative contributions of each radical adduct to the composite ESR spectrum were influenced by the concentration of the spin trap. Computer simulation of the experimental data obtained at various 5,5-dimethyl-1-pyrroline N-oxide (DMPO) concentrations was used to quantitate the contributions of each radical adduct to the composite ESR spectrum. The alkoxyl radical was the initial radical produced during the reaction. Experiments with 2-methyl-2-nitrosopropane identified the carbon-centered adducts as those of the methyl radical, hydroxymethyl radical, and a secondary carbon-centered radical. The reaction did not require NADPH-cytochrome P450 reductase or NADPH. It is concluded that the reaction involves the initial homolytic scission of the peroxide O-O bond to produce the cumoxyl radical. Methyl radicals were produced from the beta-scission of the cumoxyl radical. The peroxyl adduct was not observed in the absence of molecular oxygen. We conclude that the DMPO peroxyl radical adduct detected in the presence of oxygen was due to the methylperoxyl radical formed by the reaction of the methyl radical with oxygen. At a higher P450 concentration, a protein-derived radical adduct was also detected.

Animals↗
PubMedDate not supplied

Fluconazole therapy of oropharyngeal candidiasis in a patient with multiple endocrine failure does not correlate with Candida albicans susceptibility to fluconazole in vitro.

We report a case of oropharyngeal and oesophageal candidiasis in a 23-year-old man with endocrinopathy syndrome. Multiple episodes of infection were treated with topical miconazole, oral ketoconazole (200 mg daily) or oral fluconazole (50 mg daily) over a period of 7 years. The final episode failed to respond to ketoconazole (200 mg daily) or fluconazole (200 mg daily), but was treated successfully by increasing the fluconazole dose to 400 mg daily for 6 months. The patient was maintained on fluconazole 200 mg daily without relapse. Serial Candida albicans isolates from the oral cavity were clonally related by RFLP analyses of genomic DNA, and were resistant to fluconazole, ketoconazole and itraconazole in vitro. We conclude that fluconazole 400 mg daily is effective against oropharyngeal and oesophageal candidiasis in a patient with endocrinopathy syndrome, despite the infecting Candida albicans strains being resistant to azole antifungals in vitro.

Adult↗
PubMedDate not supplied

Efficacy of fluconazole in prophylaxis and treatment of experimental Candida endocarditis.

The efficacy of fluconazole, a bis-triazole antifungal agent, for prophylaxis and treatment of endocarditis due to Candida albicans and Candida parapsilosis is assessed in a rabbit model. Fourteen daily injections of fluconazole at doses of 20 and 10 mg/kg of body weight eradicated C. albicans and C. parapsilosis, respectively, from the cardiac vegetations in all animals tested. Amphotericin B (3 mg/kg) and flucytosine (35 mg/kg) both singly and in combination failed to achieve eradication in 100% of the animals. A two-dose prophylactic regimen of 30 mg of fluconazole/kg was consistently successful in preventing experimental endocarditis caused by C. albicans or C. parapsilosis.

Amphotericin B↗
PubMedDate not supplied

Relation between mouth and haematogenous infection in total joint replacements.

OBJECTIVE: To investigate the source of infections associated with orthopaedic prostheses. DESIGN: Analysis of four infections of prosthetic joints with case records; minimum inhibitory and minimum bactericidal concentrations and sodium dodecylsulphate polyacrylamide gel electrophoresis of the cell wall polypeptides of the Streptococcus sanguis isolates from the mouth and infected prostheses; examination of the patients' mouths for periodontal disease and caries. SUBJECTS: Four adults (three men) aged 58-83. RESULTS: For each patient the strain of S sanguis isolated from the mouth was indistinguishable from that isolated from the prosthesis. All patients had severe periodontal disease and caries. CONCLUSIONS: The mouth was probably the source of bacterial infection in the prosthetic joints of these patients; the route of infection was possibly haematogenous. Incipient oral infection should be treated before joint replacement, and oral health should be maintained indefinitely.

Aged↗
PubMedDate not supplied

Oral flora of elderly patients following acute medical admission.

The human oral microflora is diverse and is usually predominately composed of Gram-positive bacteria. It is uncommon to find Gram-negative bacilli (GNB) in healthy mouths. The incidence of infection with GNB rises in institutionalised, frail elderly subjects. There is also evidence of an association between intra-oral GNB presence and denture wearing. There have been few studies which have investigated intra-oral GNB carriage in acutely ill elderly patients. The aim of this study was to evaluate the oral flora of a group of elderly patients during an acute medical admission and to investigate any associations between the oral microflora and existing medical or oral factors. A total of 28 patients (17 females and 11 males; age: 74-93 years) on a care for the elderly ward were studied. Epidemiological data, detailed medical histories and oral examinations were undertaken. In addition, oral swabs of the palate area were taken to determine their oral flora. Twelve (43%) of the patients had GNB in their oral cavities. These patients were suffering from a variety of medical conditions and were on various drug regimes. There was a correlation between oral GNB presence and denture use. There was no association between GNB presence and denture hygiene. As oropharyngeal GNB colonisation can be associated with infections such as aspiration pneumonia, it is important in patients at risk that intra-oral organisms are identified and managed.

Aged↗
PubMedDate not supplied

Acute stroke predisposes to oral gram-negative bacilli -- a cause of aspiration pneumonia?

OBJECTIVES: To assess any change in the oral flora in the mouths of stroke patients during the acute and rehabilitation phases and to determine whether this is related to episodes of aspiration pneumonia and clinical outcome. MATERIALS AND METHODS: This observational study was carried out in hospital wards in a University teaching hospital. The subjects were patients immediately post-stroke and during the rehabilitation period, acute admissions and a group of healthy volunteers. An assessment of dentition and swallow in the presence or absence of oral aerobic gram-negative bacilli (AGNB) was correlated. RESULTS: Of the acute stroke patients 52% had an unsafe swallow. AGNB carriage was documented in 34% of the acute stroke group. Of the 11 patients who died 55% had AGNB, 73% had an unsafe swallow and 36% had a combination of both. CONCLUSION: AGNB is a common finding in acute stroke patients. It is not a consequence of age or acute hospitalisation and is associated with an unsafe swallow and a higher mortality.

Aged↗
PubMedDate not supplied

A practical guide to antibiotic prophylaxis in restorative dentistry.

The purpose of this paper is to review the principles and practicalities of antibiotic prophylaxis in medically compromised patients who require restorative dentistry. Guidelines for the management of patients who are susceptible to infection are given. The importance of oral health and the rational use of both local and systemic antimicrobial prophylaxis is described.

Antibiotic Prophylaxis↗