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Biomedical subjects

R Thomas

Publications and source records attributed to R Thomas.

At least 253 records · Page 14Linked to original sources
PubMed1998

Nosocomial infections: prospective survey of incidence in five French intensive care units.

OBJECTIVE: To assess the incidence and to evaluate the feasibility of inter-unit continuous surveillance of intensive care unit (ICU)-acquired infections. DESIGN: Prospective multicentre, longitudinal, incidence survey. SETTING: Five ICUs in university hospitals in western France. PATIENTS: All patients admitted to the ICU during two 3-month periods (1994-1995). MEASUREMENTS AND RESULTS: The main clinical characteristics of the patients, ICU-acquired infections, length of exposure to invasive devices and the micro-organisms isolated were analysed. The study included 1589 patients (16970 patient-days) and the infection rate was 21.6 % (13.1 % of patients). The ventilator-associated pneumonia rate was 9.6 %, sinusitis 1.5 %, central venous catheter-associated infection 3.5 %, central venous catheter-associated bacteraemia 4.8 %, catheter-associated urinary tract infection 7.8 % and bacteraemia 4.5 %. The incidence density rate of ICU-acquired infections was 20.3% patient-days. Ventilator-associated pneumonia and sinusitis rates were 9.4 and 1.5% ventilation-days, respectively. Central venous catheter-associated infection and central venous catheter-associated bacteraemia rates were 2.8 and 3.8% catheter-days, respectively. The catheter-associated urinary tract infection rate was 8.5% urinary catheter-days and the bacteraemia rate 4.2% patient-days. Six independent risk factors for ICU-acquired infection were found by stepwise logistic regression analysis: absence of infection on admission, age > 60 years, length of stay, mechanical ventilation, central venous catheter and admission to one particular unit. A total of 410 strains of micro-organisms were isolated, 16.8 % of which were Staphylococcus aureus (58.0% methicillin-resistant). CONCLUSION: This prospective study using standardised collection of data on the ICU-acquired infection rate in five ICUs identified six risk factors. It also emphasized the difficulty of achieving truly standardised definitions and methods of diagnosis of such infections.

Catheters, Indwelling↗
PubMed1998

1997 American Urological Association Gallup survey: Changes in diagnosis and management of prostate cancer and benign prostatic hyperplasia, and other practice trends from 1994 to 1997.

PURPOSE: The American Urological Association first commissioned the Gallup Organization to conduct a study to assess urologist practice patterns in 1992. We present the results of the 1997 survey, the sixth consecutive Gallup survey performed for the Association. MATERIALS AND METHODS: A random sample of 502 American urologists who had completed urological residency and practiced at least 20 hours weekly in 1996 was interviewed by telephone in February and March 1997. RESULTS: Emerging trends showed significant changes since 1994 in how urologists diagnosed and treated prostate cancer. The survey revealed a significant change in the tests routinely ordered to stage newly diagnosed prostate cancer and for diagnostic evaluation of patients with benign prostatic hyperplasia. CONCLUSIONS: Urologists are becoming more cost conscious and effective in ordering pretreatment testing. Urologists are becoming more oriented toward medical treatment for the management of benign prostatic hyperplasia, and less laser surgery is being performed.

Adult↗
PubMed1998

Subspecialization, recruitment and retirement trends of American urologists.

PURPOSE: Trends of urology workforce, subspecialization, recruitment practices, retirement planning, practice characteristics and managed care impacts in the United States were assessed. MATERIALS AND METHODS: In February 1996 the executive interviewing branch of The Gallup Organization selected randomly and interviewed by telephone 507 practicing urologists in the United States who had provided urological patient care for more than 20 hours per week, practiced in 1995 and completed a urological residency program. RESULTS: Several important issues emerged. Urologists think we may be training too many urologists, subspecialty board certification would be a divisive issue to urology as a whole and 90% of urologists have an active retirement plan, although 23% are not funding the plan fully. CONCLUSIONS: The American Urological Association Gallup Poll, as refined by the Health Policy Survey and Research Committee, continues to be a unique and valuable tool in assessing practice patterns, gathering demographic data and measuring opinions of the American urologist. This information will help us chart our way to the twenty-first century.

Adult↗
PubMed1998

Retroperitoneal and pelvic extraperitoneal laparoscopy: an international perspective.

OBJECTIVES: To assess technical preferences and current practice trends of retroperitoneal and pelvic extraperitoneal laparoscopy. METHODS: A questionnaire survey of 36 selected urologic laparoscopic centers worldwide was performed. RESULTS: Twenty-four centers (67%) responded. Overall, 3988 laparoscopic procedures were reported: transperitoneal approach (n = 2945) and retroperitoneal/extraperitoneal approach (n = 1043). Retroperitoneoscopic/extraperitoneoscopic procedures included adrenalectomy (n = 74), nephrectomy (n = 299), ureteral procedures (n = 166), pelvic lymph node dissection (n = 197), bladder neck suspension (n = 210), varix ligation (n = 91), and lumbar sympathectomy (n = 6). Mean number of total laparoscopic procedures performed in 1995 per center was 41 (range 5 to 86). Major complications occurred in 49 (4.7%) patients and included visceral complications in 26 (2.5%) patients and vascular complications in 23 (2.2%). Open conversion was performed in 69 (6.6%) patients, electively in 41 and emergently in 28 (visceral injuries, n = 16; vascular injuries, n = 1 2). Retroperitoneoscopy/extraperitoneoscopy is gaining in acceptance worldwide: in 1993, the mean estimated ratio of transperitoneal laparoscopic cases versus retroperitoneoscopic/ extraperitoneoscopic cases per center was 74:26; however, in 1996 the ratio was 49:51. CONCLUSIONS: Retroperitoneoscopy and pelvic extraperitoneoscopy are important adjuncts to the laparoscopic armamentarium in urologic surgery. The overall major complication rate associated with retroperitoneoscopy/extraperitoneoscopy was 4.7%.

Humans↗
PubMed1998

Endopyelotomy. Retrograde ureteroscopic approach.

Ureteroscopy is a natural extension of a urologist's practice. This article describes technical details and results using the ureteroscopic approach to treat ureteropelvic junction obstruction. With a variety of treatment options available, this approach compared favorably.

Ambulatory Surgical Procedures↗
PubMed1998

Scintimammography with 99mTc-MDP: experience of the National Cancer Institute of Naples.

The role of scintimammography with 99mTc-MDP was investigated in patients with mammographic or clinical evidence of breast lesions, suspicious for malignancy, in our Department at the National Cancer Institute of Naples. The end-point of the study was to assess the uselfulness of this test in diagnosing or ruling out breast cancer in more than 2000 women. Scintimammography results were compared with those of mammography and ultrasound and categorized according to histological findings. Overall sensitivity was 92%, specificity was 90%, and accuracy 91%. Sensitivity was affected by the lesions exceeding 12 mm and specificity by sclerotic and/or hyaline or myxoid fibroadenomas, which may be positive. The major advantages of scintimammography appeared in the study of calcifications without a mass and of the indirect mammographic signs of breast cancer, such as distortion and asymmetry. Scintimammography with 99mTc-MDP is a reliable, safe and highly cost-effective procedure to diagnose or to rule out breast cancer, after mammography and ultrasound have yielded questionable results.

Breast Neoplasms↗
PubMed1998

Posterior capsule rupture after blunt trauma.

Two patients had rupture of the posterior lens capsule caused by blunt trauma. In both, the typical fibrosed edges of the posterior capsule breaks were clearly visible and could be documented preoperatively.

Adult↗
PubMed1998

Weekly paclitaxel-cisplatin administration with G-CSF support in advanced breast cancer. A phase II study.

PURPOSE: In a previous phase I study we found the MTDs of paclitaxel and cisplatin when given together weekly, with or without G-CSF support, in patients with advanced solid tumors. The present study was conducted to define the toxicity and efficacy of this regimen, when used with G-CSF support, in chemotherapy-naive or pretreated patients with advanced breast cancer, and to compare the antiproliferative activity of paclitaxel-cisplatin and paclitaxel-doxorubicin combinations on two human breast cancer cell lines. METHODS: Patients with metastatic breast cancer received weekly paclitaxel (as a 3-hour i.v. infusion) at the dose of 85 mg/m2 (75 mg/m2 in pretreated women) followed by cisplatin (40 mg/m2) for a minimum of 6 weeks. An additional 6 weekly cycles were delivered in patients showing absence of documented disease progression after the first 6 weeks. After the 12th cycle only patients who had shown a substantial tumor shrinkage received 6 further cycles. G-CSF 5 microg/kg was also given, SC on days 3 to 5 of each week, for the whole duration of chemotherapy. The combination of paclitaxel with cisplatin or doxorubicin was also tested in vitro on two breast cancer cell lines (MCF-7 and MDAMB-231). RESULTS: Forty-three women with metastatic breast cancer entered this trial between June 1995 and January 1997. Twenty-seven patients were previously untreated for their metastatic disease (but 23 had previously received adjuvant chemotherapy). The dominant site of disease involvement was visceral in 23, bone in 13, and soft tissues in 7 patients. Seven complete and 15 partial responses were observed in unpretreated patients, while no complete and 6 partial responses were achieved in the pretreated population. The overall response rate, assessed on an 'intent to treat' basis, was 81% (26% CRs) in patients unpretreated for metastatic disease and 37% in those who had received one or more previous chemotherapy regimens. Eighteen responder patients had previously received anthracyclines either as adjuvant chemotherapy (12) or in the treatment of metastatic disease (6). At a median potential follow-up of 12 (range, 3-21) months, 14/27 unpretreated and 12/16 pretreated patients had shown disease progression. The median time to treatment failure was 13 and 7 months, respectively, in the 2 subgroups. The 1-year survival probability was 95% in unpretreated patients. The treatment showed a moderate toxicity in both subgroups of patients. Both hematological toxicity and peripheral neuropathy occurred more frequently in pretreated patients. Treatment-related deaths did not occur, and severe myelosuppression was observed only in pretreated patients with massive liver involvement. Delays in chemotherapy administration were very uncommon, especially during the first 6 treatment cycles, and the average actually delivered dose intensity exceeded 90% in unpretreated patients. The in vitro data on MCF-7 and MDA-MB-231 human breast cancer cell lines showed that exposure to the combination of cisplatin and paclitaxel produced a tumor cell killing similar to that achievable with equivalent concentrations of doxorubicin and paclitaxel. CONCLUSIONS: Weekly paclitaxel and cisplatin with G-CSF support is an active and particularly well tolerated treatment for patients with either unpretreated or pretreated metastatic breast cancer. This approach seems quite effective also in patients relapsing after anthracycline-based adjuvant chemotherapy. In view of the negligible hematological toxicity associated with this regimen, further clinical trials testing the addition of non cross-resistant drugs to this combination should be performed.

Adult↗
PubMed1998

Interaction of apolipoprotein E epsilon 4 with other genetic and non-genetic risk factors in late onset Alzheimer disease: problems facing the investigator.

The Apolipoprotein E4 allele (Apo-epsilon4) is the major susceptibility gene for late onset Alzheimer Disease (AD) but epidemiological data suggest that the effect of this allele is modified in different individuals by genetic or environmental factors. Age and head injury are major non-genetic factors modifying the Apo-epsilon4 risk. There is conflicting data as to whether alleles of other chaperon proteins (such as alpha-1-antichymotrypsin (ACT)) or Apo-epsilon4 receptors (such as the VDRL receptor) modify the Apo-epsilon4 risk for AD. We analyze problems posed by genetic association studies including those of multiple comparisons and selection of controls, the latter problem exacerbated by the wide variations in Apolipoprotein E allele frequencies observed in different groups and localities.

Alzheimer Disease↗
PubMed1998

Tumor clearance of technetium 99m-sestamibi as a predictor of response to neoadjuvant chemotherapy for locally advanced breast cancer.

PURPOSE: Since we have previously shown that the efflux rate of technetium 99m (99mTc) sestamibi, a transport substrate of P-glycoprotein (Pgp), is directly correlated with Pgp levels in untreated breast carcinoma, we tested whether tumor clearance of 9mTc-sestamibi may be predictive of therapeutic response to neoadjuvant chemotherapy in patients with locally advanced breast cancer. PATIENTS AND METHODS: Thirty-nine patients with stage III disease, median tumor diameter 5.8 cm (range, 3 to 10) were enrolled onto this prospective clinical trial and underwent 99mTc-sestamibi scan before neoadjuvant chemotherapy. Patients were injected intravenously (i.v.) with 740 MBq of 99mTc-sestamibi; a 15-minute dynamic study was performed, and static planar images were obtained at 0.5, 1, 2, and 4 hours. The time to half clearance of 99mTc-sestamibi was calculated in each patient from decay corrected time-activity curves using a monoexponential fitting. Patients were treated with epirubicin 150 mg/m2 i.v. every 2 weeks for three courses and then underwent surgery within 3 weeks from the completion of chemotherapy. Residual tumor was assessed by pathologic examination of mastectomy specimens. RESULTS: Seventeen of 39 patients showed a rapid tumor clearance of 9mTc-sestamibi (time to half clearance [t1/2] < or = 204 minutes) and 15 of these 17 (88%) showed a highly cellular macroscopic residual tumor at histology that indicated lack of tumor response to neoadjuvant chemotherapy. In contrast, only eight of 22 (36%) with prolonged retention of 99mTc-sestamibi (t1/2 > 204 minutes) showed residual macroscopic tumor at histology (Fisher's exact test, P < .01). CONCLUSION: A rapid tumor clearance of 99mTc-sestamibi may predict lack of tumor response to neoadjuvant chemotherapy with drugs affected by the multidrug-resistant phenotype in patients with locally advanced breast carcinoma.

Adult↗
PubMed1998

Management of phacolytic glaucoma: experience of 135 cases.

We retrospectively analyzed 135 eyes with phacolytic glaucoma. A trabeculectomy was added to standard cataract surgery if symptoms endured for more than seven days, or if preoperative control of intraocular pressure (IOP) with maximal medical treatment was inadequate. In the early postoperative period, IOP was significantly lower in the combined surgery group (89 eyes) compared to the cataract surgery group (46 eyes) (p < 0.001). At 6 months there was no difference in IOP or visual acuity between the two groups. There were no serious complications related to trabeculectomy. It is reasonable to conclude that in eyes with a long duration of phacolytic glaucoma, addition of a trabeculectomy to cataract surgery is safe, prevents postoperative rise in intraocular pressure and decreases the need for systemic hypotensive medications. A randomized trial is on to further address this question.

Adult↗
PubMed1998

Gonioscopy.

Gonioscopy forms part of a complete ophthalmic examination and is mandatory for the diagnosis and management of glaucoma. Gonioscopy permits identification of eyes at risk for closure and detects angle abnormalities that could have diagnostic and therapeutic implications. The technique of gonioscopy, its value in management, and guidelines for routine use are discussed in this paper.

Cornea↗
PubMed1998

Laws for the dynamics of regulatory networks.

We start our analysis from historical but too seldom quoted papers by Delbrück, Noveck & Weiner, Cohn & Horibata and Monod & Jacob. We try to show how it became possible to draw a line coupling cell differentiation to the physical concept of multistationarity, and the latter to the concept of positive feedback circuits. Two laws give the minimal logical ingredients required for differentiative and homeostatic regulations. It is briefly shown how they can be used to treat such complex dynamics as deterministaic chaos, which, admittedly, does not yet belong to the corpus of developmental biology. It was taken as a challenge to express our ideas here in purely verbal terms, avoiding any formal treatment.

Animals↗