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Biomedical subjects

J Fenton

Publications and source records attributed to J Fenton.

At least 19 recordsLinked to original sources
PubMed1997

Emergence of further serotypes of multiple drug-resistant Streptococcus pneumoniae in Queensland.

We describe 27 cases of multiple drug-resistant pneumococcal infection in Queensland children (7 cases) and adults (20 cases), between February 1995 and October 1996. Seven patients had invasive disease. Serotypes were those commonly associated with paediatric infections and included types 19F (15 strains), 14 (6), 23F (4), 6A (1) and 19A (1). No rifampicin or vancomycin resistance was encountered. However, pneumococci fully resistant to cotrimoxazole, erythromycin and tetracycline were isolated from 25 of 27 cases (93%). Strains with high level resistance to penicillin and chloramphenicol were also recovered from 16 (59%) and 19 (70%) patients respectively. Twelve of 16 penicillin-resistant isolates showed intermediate resistance to ceftriaxone and two strains were fully resistant to this antibiotic. Clones of types 19F and 14 pneumococci, each with two distinctive resistance patterns, appear to be established in south-east Queensland.

Adult↗
PubMed1996

Occult pharyngeal perforation secondary to 'pencil injury'.

Palatopharyngeal injuries due to impaction of rigid objects held in the mouth are common. Most are essentially innocuous injuries requiring no specific treatment. However, there is the potential for perforation of the pharyngeal wall with the subsequent development of serious infection such as retropharyngeal abscess or mediastinitis. This possibility is more likely to be suspected in the presence of a visible laceration or puncture wound at the site of impact in the mouth or pharynx. We report three cases in which occult pharyngeal perforation occurred without any clinical signs of breech of the pharyngeal wall. In all cases a lateral soft tissue neck X-ray was diagnostic of perforation, showing the presence of retropharyngeal air. We, therefore, advocate the routine performance of soft tissue neck X-rays in all patients who present with a history of falling on a rigid object held in the mouth.

Adolescent↗
PubMed1995

The radio-opacity of fishbones: a cadaveric study.

Lateral neck radiographs performed to localize impacted fishbones have a low sensitivity. The differing radio-opacities of the bones of various fish species may be a reason for this. A cadaver head and neck and the rib bones of 10 species of fish were used in this study. A laryngoscope was used to introduce a fishbone into the vallecula and then into the hypopharynx of the cadaver. A lateral radiograph was taken in each case. Ten control films were taken. The radiographs were independently reviewed by a consultant radiologist and otolaryngologist. The presence and position of any bone seen was noted. There was no inter-observer variation. All species of fishbone were visible. One bone was not seen by either observer. Visualization of fishbones is more dependent on position than their degree of radio-opacity. Routine radiography is recommended.

Animals↗
PubMed1995

[Pelvic lymph node invasion in cancer of the uterine cervix].

Pelvic lymph node invasion is an important prognostic factor for cervical cancer. It is generally accepted that iliac lymph nodes must be treated systematically, but the extent of lymph node dissections is open to discussion. One hundred and eighty two cases of cervical cancer with lymph node invasion were treated at the Institut Curie between 1960 and 1988, by colpohysterectomy with lymph node dissection (168 cases) combined with preoperative brachytherapy and, in some cases, pre- and/or postoperative radiotherapy; in 14 cases, only an exploratory operation was performed. External iliac lymph node invasion was found in 95% of cases, situated in the middle and internal chains. Common iliac lymph node invasion was found in 24% of cases, but was only exceptionally isolated (3%). It is therefore possible, by means of well defined, localized external iliac dissection, with frozen section histological examination, to determine the exact lymph node status. Lumboaortic lymph node invasion was found in 8.2% of cases. The overall survival rate was 49% at 5 years and 40.5% at 10 years. Factors which influence survival are: the cervical volume (p = 0.015), the unilateral or bilateral nature of invasion (p = 0.0015), the number of lymph nodes invaded (two or more than two) (p = 0.0001), capsular rupture (p = 0.0008), lymph node adhesions other than venous (p = 0.0002), common iliac invasion (p = 0.0001). On Cox's model, the principal factors were the number of lymph nodes invaded, adhesion other than venous, common iliac invasion; on the other hand, venous adhesion does not modify the prognosis. The five-year survival rates following external iliac dissections and complete pelvic dissections were not significantly different. Finally, postoperative radiotherapy ensured a higher five-year survival rate than preoperative radiotherapy, but the cervical volume was greater and primary invasion was more frequent in these cases. Postoperative radiotherapy of 15 grays after preoperative radiotherapy did not appear to modify the survival and therefore appears to be useless.

Adult↗
PubMed1995

[Prognostic factors in endometrial cancer: apropos of 206 cases treated at the Curie Institute].

From January 1, 1983 to December 31, 1990 two hundred and six patients with an invasive, non metastatic endometrial carcinoma were first treated at Institut Curie. Initial tumoral staging (TNM) was as follows: stage Ia: 48%, stage Ib: 31%, stage II: 15% and stage III-IV: 6%. Total hysterectomy or colpohysterectomy was performed in 186 cases, with a bilateral oophorectomy in 180 cases. Bilateral limited pelvic lymphadenectomy was performed in 116 cases. Brachytherapy was performed in the pre-operative setting in 25 cases, in the post-operative setting in 134 cases. Only five patients had brachytherapy alone, because of poor medical condition. External irradiation was exclusive in 15 cases and added to surgery for 68 patients. Median follow-up is 61 months (8-122 months). Five-year survival rate is 77% (71-83%); 5-year specific survival rate is 81% (75-87%). Independent prognostic factors for survival in multivariate analysis (Cox regression model) are tumoral stage (p < 0.0001), ovarian involvement (p < 0.0001), histologic node involvement (p = 0.005) and grade (p = 0.01). For local relapse, independent risk factors in the same analysis are ovarian involvement (p = 0.0004), tumoral stage (p = 0.01), age (p = 0.02) and histologic involvement of cervix (p = 0.04). For distant failure, independent risk factors are histologic node involvement (p = 0.0001), tumoral stage (p = 0.002) and grade (p = 0.003).

Adenocarcinoma↗
PubMed1994

Tympanostomy tubes and early post-operative otorrhea.

Otorrhea is a recognized complication of tympanostomy tube insertion. This may be caused by external contamination or by the pre-existing conditions in the middle ear cleft. Some surgeons try to reduce the risk of surgical contamination by using a non-touch technique, never allowing the gloved hand to come into contact with the tympanostomy tube. A prospective study was carried out on 66 children to evaluate the efficacy of the non-touch technique. One tympanostomy tube was inserted by the non-touch method with the contralateral ear acting as a touched control in each patient. Postoperative otorrhea occurred within 10 days in 1.67% of the non-touch ears and in 1.67% of the controls. This study demonstrates a low incidence of otorrhea in the early post-operative period with either technique. Time-consuming and costly sterile precautions are unnecessary for this common procedure.

Child↗
PubMed1994

The role of Chlamydia pneumoniae in severe acute tonsillitis.

Chlamydia pneumoniae has been implicated as a cause of tonsillitis and pharyngitis, but the incidence has varied from one to 19 per cent in various studies. We investigated 51 patients admitted to University College Hospital, Galway, with severe tonsillitis. Throat swabs were examined for evidence of Chlamydia pneumoniae using a direct monoclonal antibody test. Blood was taken for serology from 45 patients. A further specimen was taken at six weeks. A control group of 32 blood bank sera was used. Mean hospital stay was three days (one to eight). Five patients (10 per cent) were monospot positive. Chlamydia pneumoniae was identified by direct immunofluorescence on a tonsillar swab from one patient who did not seroconvert. IgG antibody was identified in 13 cases (29 per cent) and in seven of the control group (22 per cent). No serological evidence of recent infection was found. Chlamydia pneumoniae was not found to be a cause of severe acute tonsillitis in our study group.

Acute Disease↗
PubMed1994

alpha-thrombin bound to extracellular endothelial matrix induces pronounced fibrin deposition and platelet thrombus growth in flowing non-anticoagulated human blood.

Previous studies have shown that thrombin binds to the extracellular endothelial matrix and remains biologically active. In the present study, the role of matrix-bound alpha-thrombin in thrombus formation was investigated by utilizing a model system of thrombogenesis. Plastic cover-slips coated with either matrix-bound alpha-thrombin or matrix-bound active site inactivated thrombin (DIP-alpha-thrombin) were positioned in parallel-plate perfusion chambers and subsequently exposed to non-anticoagulated human blood at a venous wall shear rate of 100/s. The blood was drawn directly from an antecubital vein by a roller pump placed distally to the perfusion chamber. The thrombotic deposits on the matrix, fibrin deposition and platelet thrombus volume, were morphologically evaluated. Matrix-bound alpha-thrombin enhanced the fibrin deposition and thrombus volume on matrices of non-stimulated endothelium with 91% (P < 0.001) and 94% (P < 0.05), respectively. In contrast, binding of DIP-alpha-thrombin to matrices of stimulated endothelium reduced the fibrin deposition by 33% (P < 0.05), but had no effect on the platelet thrombus volume. Translocation of thrombin molecules from upstream matrix areas to binding sites farther downstream on the matrix was indicated in experiments with matrices of stimulated endothelium, which showed enhanced fibrin deposition on downstream areas. Our findings are compatible with a prominent role for matrix-bound alpha-thrombin in thrombogenesis, and in particular on endothelial matrices without tissue factor. The role of matrix-bound alpha-thrombin on tissue factor containing matrices appears less prominent, although it is significant.

Blood Coagulation↗
PubMed1993

Age as prognostic factor in premenopausal breast carcinoma.

Whether or not young age at diagnosis is an adverse prognostic factor in breast cancer has long been controversial, in part because much previous work has not taken due account of menopausal status and confounding factors. We have analysed the influence of age on prognosis in a consecutive series of 1703 patients with stage I-III breast cancer. All were premenopausal and all were treated in one centre (Institut Curie, Paris) between 1981 and 1985. Mean age was 44 years (range 23-55) and median follow-up was 82 months. Younger patients had significantly lower survival rates and higher local and distant relapse rates than older patients. The hazard rate of relapse decreased over time in the youngest age group (< or = 33) to reach that of older patients after 5 years. The relation between the hazard of recurrence and age was a continuous one, best fitted by a log-linear function and indicating a 4% decrease in recurrence for every year of age. Multivariate analysis of both survival and disease-free interval demonstrated that the worse prognosis of young age was independent of other factors such as clinical tumour size, clinical node status, histological grade, hormone receptor status, locoregional treatment procedure, and adjuvant systemic therapy. This difference in outlook has yet to be explained biologically but it does suggest the need for a closer look at the natural history of breast cancer in young women.

Adult↗
PubMed1993

Blunt cardiac trauma: survival after bichamber rupture.

Rupture of cardiac chambers after nonpenetrating blunt thoracic trauma is being recognized with increasing frequency. Despite a high mortality rate, survival after repair of a single-chamber rupture is widely reported. Bichamber cardiac rupture is less frequent, and we report a patient who survived this injury.

Adult↗
PubMed1991

Abnormal M-wave responses during exercise in myotonic muscular dystrophy: a Na(+)--K+ pump defect?

Maximum M-waves (muscle compound action potentials) were studied in the abductor pollicis brevis (APB), extensor digitorum brevis (EDB), and tibialis anterior (TA) muscles of 12 patients with myotonic muscular dystrophy (MMD) and in the same number of control subjects, matched for age and sex. The peak-to-peak amplitudes and voltage-time areas of the responses were measured at rest, between 40 maximum voluntary contractions (each lasting 3 s) and also during a 2-min recovery period. In 34 of the 36 control muscles the M-waves potentiated during the period of intermittent voluntary contractions. In the MMD patients, however, the M waves exhibited initial declines in 25 of 30 muscles. In the APB and EDB muscles the normalized mean values for the smallest M-waves, recorded during the 350 s total observation periods, differed significantly between the 2 groups of subjects. It is suggested that the sarcolemmal Na(+)-K+ pump has a raised threshold for activation in MMD patients.

Adult↗
PubMed1991

Endogenous platelet fibrinogen surface expression on activated platelets.

Intracellular platelet fibrinogen surface expression was studied in arabinogalactan-purified, resting, and thrombin-stimulated platelets. Platelet fibrinogen is derived from endocytosis of plasma fibrinogen by megakaryocytes. Like a variety of other adhesive proteins, it is stored in the platelet alpha-granule. Platelet fibrinogen surface expression was studied by using the antigen-binding fragments of a murine monoclonal antibody to platelet fibrinogen, F26, and an immunopurified polyclonal antifibrinogen antibody. Studies correlating platelet fibrinogen surface expression with the presence of the glycoprotein IIb-IIIa (GPIIb-IIIa) complex showed that in the presence of ethylene glycol tetraacetic acid (EGTA) at 37 degrees C, neither the GPIIb-IIIa complex nor platelet fibrinogen was expressed on the surface of thrombin-activated platelets. Similar experiments performed in the presence of EGTA and calcium showed proportional expression of the GPIIb-IIIa complex and platelet fibrinogen. The addition of Arg-Gly-Asp-Ser-containing peptides, the pentadecapeptide of the fibrinogen gamma-chain carboxy terminus, or the monoclonal antibody 10E5, when directed against the GPIIb-IIIa complex before thrombin activation, inhibited 65% to 94% of the platelet fibrinogen expression, as determined with the polyclonal and monoclonal antigen-binding fragments. When these same inhibitory agents were added immediately after or 5 minutes after thrombin, the amount of inhibition decreased significantly. Similar studies with a washed platelet system revealed that when the inhibitors of platelet fibrinogen expression were added before thrombin stimulation, the degree of inhibition observed was only 24% to 38%. This suggests that the major portion of platelet fibrinogen expression involves the release of platelet fibrinogen and its subsequent binding to GPIIb-IIIa. This binding may occur within the open canalicular system or on the platelet surface; in either case, wherever the site of released platelet fibrinogen binding occurs, it can be markedly inhibited by the RGD-containing peptides and the gamma-chain fibrinogen peptides. Approximately 10% to 30% of platelet fibrinogen may be expressed prebound to a platelet receptor, or else it is released and binds to a platelet receptor other than the GPIIb-IIIa complex.

Amino Acid Sequence↗
PubMed1991

Thrombin-induced leukopenia and thrombocytopenia are attenuated by PAF antagonist WEB 2086.

Thrombin has been shown to increase pulmonary transvascular permeability in vivo. This permeability change appears to be dependent on polymorphonuclear leukocytes (PMNs). In vitro, thrombin has been demonstrated to increase PMN adherence to endothelial cells coincident with generation of platelet activating factor (PAF) by endothelial cells. These observations have led to the suggestion that PAF mediates, in part, the attachment of PMNs to endothelial cells. We examined this hypothesis in vivo and in vitro with a specific PAF receptor antagonist, WEB 2086. Prior infusion of WEB 2086 into conscious sheep significantly attenuated the drop in peripheral blood PMN counts observed during and after infusion of alpha-thrombin (30 NIH U/kg). These data suggest that WEB 2086 prevented PMN margination on endothelial cells. WEB 2086 also attenuated the thrombocytopenia seen after thrombin infusion and ameliorated the thrombin-induced hypoxemia and hemoconcentration. WEB 2086 did not affect the thrombin-induced hemodynamic response, the degree of intravascular coagulation as assessed by fibrin degradation product generation, or thromboxane B2 generation. In vitro, WEB 2086 prevented the augmented adherence of sheep PMNs to sheep endothelial cell monolayers after thrombin stimulation. The results of the present study are consistent with the hypothesis that PAF mediates, at least in part, thrombin-induced leukopenia and thrombocytopenia in vivo.

Animals↗
PubMed1990

[Local recurrence of rectal cancers. Multidimensional analysis by anatomoclinical factors and role of irradiation].

Pre- or postoperative radiation therapy reduces the incidence of local recurrence after surgical treatment of rectal carcinoma. Factors related to local recurrence were analyzed retrospectively by uni- and multivariate analysis. One hundred and fifty-five patients (mean age: 65 years) were operated on with curative intent between 1967 and 1984. Ninety-four patients (46 patients having abdominoperineal resections (APR), and 48 having anterior resections) did not receive radiation therapy. Sixty-one patients had preoperative radiation therapy followed by APR in 59 cases. Univariate analysis showed that the risk of local recurrence increased significantly with male sex (p less than 0.006), positive lymph nodes (p less than 0.01), vascular invasion (p less than 0.02), and Astler-Coller classification (p less than 0.05). Tumor located at less than 5 cm from the anal verge was significantly related to recurrence only in patients not receiving radiation therapy (p less than 0.02). Multivariate analysis including therapeutic modalities showed that local recurrence was significantly related with male sex (p less than 0.02), positive lymph nodes (p less than 0.01), and distance to anal verge (p less than 0.01). The beneficial role of radiation therapy appeared only for tumors located 5 cm or less from the anal verge. Prognostic scores were established using these variables and the effect of irradiation was evaluated according to these scores. Radiation therapy significatively reduced the risk of local recurrence in low-risk patients, i.e., female with low-lying tumor and with negative lymph nodes (p less than 0.03).(ABSTRACT TRUNCATED AT 250 WORDS)

Adenocarcinoma↗
PubMed1990

[Invasive cancer of the uterine cervix in young women: retrospective study of 236 cases].

The study of cases treated between 1970 and 1984 at the Institut Curie, in women aged 40 years and under, was undertaken in order to determine the influence of age on prognosis. The incidence of these cases was stable throughout the 15 years study period as was the very high incidence of earlier cases: 84.5%. Earlier cases were treated with combined radiotherapy and surgery and advanced cases with radiotherapy alone. Overall survival rate was 75% at 5 years, 60% at 10 and 15 years: but 85% for the 36-40 years of age group, 74% for the 30-35 years of age group and 67% for women aged 29 and less. Five year survival rate for operated cases is the same for the 36-40 age group as for all age patients, according to the lymph node status. In contrast, it was 85% in the N-younger group, and 30% for those patients with lymph node involvement. In conclusion, from our study it appears that the overall survival rate for women of 36 years and less, and mainly 29 years and less, is significantly lower than that for older women, and that their prognosis is especially poor in the case of lymph node involvement.

Adenocarcinoma↗
PubMed1989

M wave potentiation during and after muscle activity.

The M wave (muscle compound action potential) has been shown to enlarge between successive 3-s voluntary contractions of the human thenar and extensor digitorum brevis (EDB) muscles. The changes, which affected both the amplitude and the area of the M wave, were more obvious in the thenar than in the EDB muscles. In the thenar muscles the mean amplitude was already significantly enlarged after the first voluntary contraction and close to the maximal value by the third (mean maximal increase 23.6 +/- 12.6% of control). The increase in mean M wave area was more gradual, reaching a maximum of 29.3 +/- 14.1% at 100 s. After the voluntary thenar contractions ceased, the amplitude of the M wave subsided more rapidly than the area and had regained the control value within 50 s. The magnitude and time course of the increase in EDB M wave area (maximum change 25.9 +/- 15.2%) were similar to those of the thenar muscles; however, the subsequent decline was slower. The amplitude of the EDB M wave showed the least change, and the maximum increase (11.4 +/- 9.6%) occurred early in the postcontraction period. In both muscles the changes in M wave amplitude and area were significantly different from the control values.

Action Potentials↗