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Biomedical subjects

M Wolff

Publications and source records attributed to M Wolff.

At least 127 records · Page 7Linked to original sources
PubMed1998

Uneven distribution of K+ channels in soma, axon and dendrites of rat spinal neurones: functional role of the soma in generation of action potentials.

1. A novel method of 'entire soma isolation' was used to describe the distribution of voltage-gated K+ channels between soma, axon and dendrites of dorsal horn neurones identified in spinal cord slices of newborn rat. 2. The soma contained 36 % of total inactivating (KA) current but only 15 % of delayed rectifier (KDR) current. The axon initial segment possessed almost half (47 %) of the total KA current and 38 % of KDR current. In contrast, dendrites contained a small portion (17 %) of KA but 47 % of KDR current. 3. Under current-clamp conditions, the soma isolated from axon and dendrites was not able to generate action potentials. It passively conducted weak (</= -50 mV) and amplified pronounced (-50 to 0 mV) depolarizations but inhibited strong (>/= 0 mV) depolarizations. 4. It is concluded that the soma plays a complex role in the excitability of spinal dorsal horn neurones. It conducts passively or amplifies excitatory postsynaptic potentials on their way from dendrites and soma to the axon initial segment but it inhibits back-propagation of the action potential from the axon to the dendrites.

4-Aminopyridine↗
PubMed1998

The efficacy of live attenuated, cold-adapted, trivalent, intranasal influenzavirus vaccine in children.

BACKGROUND: Influenzavirus vaccine is used infrequently in healthy children, even though the rates of influenza in this group are high. We conducted a multicenter, double-blind, placebo-controlled trial of a live attenuated, cold-adapted, trivalent influenzavirus vaccine in children 15 to 71 months old. METHODS: Two hundred eighty-eight children were assigned to receive one dose of vaccine or placebo given by intranasal spray, and 1314 were assigned to receive two doses approximately 60 days apart. The strains included in the vaccine were antigenically equivalent to those in the inactivated influenzavirus vaccine in use at the time. The subjects were monitored with viral cultures for influenza during the subsequent influenza season. A case of influenza was defined as an illness associated with the isolation of wild-type influenzavirus from respiratory secretions. RESULTS: The intranasal vaccine was accepted and well tolerated. Among children who were initially seronegative, antibody titers increased by a factor of four in 61 to 96 percent, depending on the influenza strain. Culture-positive influenza was significantly less common in the vaccine group (14 cases among 1070 subjects) than the placebo group (95 cases among 532 subjects). The vaccine efficacy was 93 percent (95 percent confidence interval, 88 to 96 percent) against culture-confirmed influenza. Both the one-dose regimen (89 percent efficacy) and the two-dose regimen (94 percent efficacy) were efficacious, and the vaccine was efficacious against both strains of influenza circulating in 1996-1997, A(H3N2) and B. The vaccinated children had significantly fewer febrile illnesses, including 30 percent fewer episodes of febrile otitis media (95 percent confidence interval, 18 to 45 percent; P<0.001). CONCLUSIONS: A live attenuated, cold-adapted influenzavirus vaccine was safe, immunogenic, and effective against influenza A(H3N2) and B in healthy children.

Administration, Intranasal↗
PubMed1998

Peak power and pulmonary oxygen uptake during knee extension exercise--comparisons among different incremental protocols.

Four incremental protocols of knee extension exercise of different stage durations were compared to study the effect of the protocol upon power output at the last stage (Ppeak). Previous studies of knee extension have found very different power outputs with similar ergometers and these large differences have been interpreted as being the result of the fatigue due to the durations of the protocols. The knee extension device used in previous studies was modified to avoid the action of the knee and hip flexors: the subjects pushing on a lever instead of pulling a rod. In the present study five subjects performed four incremental knee extension exercises which differed with regard to stage duration (60, 90, 180 or 360 s) on this ergometer. The Ppeak, peak oxygen uptake (VO2peak) and peak heart rate (HRpeak) were measured at the end of each of these four incremental protocols. In eight subjects, the reliability of the protocols with the two shortest increments (60 and 90-s stages) was verified by measuring Ppeak at 60 s and 90 s (Ppeak60, Ppeak90) twice. The knee ergometer proposed in the present paper was easy to use without any special training and should improve the measurement of Ppeak. The Ppeak60 [49.4 (SD 5.6) W] was higher than at 180 s [Ppeak180), 43.6 (SD 5.8) W, P < 0.05] and at 360 s [Ppeak360, 43.4 (SD 5.3) W, P < 0.05]. All the other differences in Ppeak, VO2 peak and HRpeak were not significant. All correlations between Ppeak60, Ppeak90, Ppeak180 and Ppeak360 were significant, except those between Ppeak360 and Ppeak90 or Ppeak180. The effect of the stage duration on power output and oxygen uptake at the end of the knee extension exercises was not great. Consequently, the large differences in power output and oxygen uptake observed in previous studies cannot be explained by the protocol only. The significant difference between Ppeak 60 and Ppeak90 was of the order of 10% in agreement with findings in the literature using cycle ergometry. The reliability of Ppeak60 and Ppeak90 was high and the use of these protocols can be recommended if further studies show that the measurement of Ppeak, is useful in the evaluation of local endurance.

Adult↗
PubMed1998

Oral mucosal wetness in hypo- and normosalivators.

After a person swallows, a film of residual saliva covers the oral hard- and soft-tissue surfaces. Here, the thickness of this film was measured at 11 selected mucosal surfaces on each side of the mouth (22 sites total) in two groups of dry-mouth and one group of normal individuals. Each group contained 25 individuals; one of the dry-mouth groups had resting flow rates < or = 0.1 ml/min while the other and the normal had flow rates above that. Residual saliva thickness was determined by placing frying-pan-shaped filter-paper strips (Sialopaper) against the mucosa at each site for 5 s and measuring the saliva volume collected with a modified Periotron 6000 micro-moisture meter; the thickness was then calculated by dividing the collected saliva volume by the strip area. The two groups with dry-mouth symptoms had mean resting (unstimulated) saliva flow rates of 0.04 and 0.19 ml/min and mean mucosal saliva thicknesses of 22.4 and 27.8 microns, respectively. The control group had a higher mean saliva flow rate of 0.39 ml/min and mucosal saliva thickness of 41.8 microns. As was observed in a previous study on normosalivators, the various sites had a characteristic pattern of wetness, with the hard palate and lips the least moist regions. In this study, these observations, were also true in the two dry-mouth groups. Lower resting saliva flow rates were associated with lower mucosal thickness of saliva and with dryness symptoms becoming evident when hyposalivation was below about 0.1-0.2 ml/min. The characteristic pattern of mucosal wetness was not affected by saliva flow rate. As saliva readily collects in the floor of the mouth and is then spread over other mucosal surfaces upon swallowing, it was suggested that hyposalivation could also lead to the dryness symptoms because there was not enough saliva to cover the various oral surfaces, especially the palate and the lips. In this regard, a critical level of moisture was proposed as necessary to protect vulnerable mucosal surfaces from becoming dry. Lower resting saliva flow rates and correspondingly lower mucosal wetness were also associated with a more acidic salivary pH, which was shown earlier to be associated with lower dental plaque pH.

Adult↗
PubMed1998

Improving primary care residents' proficiency in the diagnosis of skin cancer.

OBJECTIVE: To determine whether a brief, multicomponent intervention could improve the skin cancer diagnosis and evaluation planning performance of primary care residents to a level equivalent to that of dermatologists. PARTICIPANTS: Fifty-two primary care residents (26 in the control group and 26 in the intervention group) and 13 dermatologists completed a pretest and posttest. DESIGN: A randomized, controlled trial with pretest and posttest measurements of residents' ability to diagnose and make evaluation plans for lesions indicative of skin cancer. INTERVENTION: The intervention included face-to-face feedback sessions focusing on residents' performance deficiencies; an interactive seminar including slide presentations, case examples, and live demonstrations; and the Melanoma Prevention Kit including a booklet, magnifying tool, measuring tool, and skin color guide. MEASUREMENTS AND MAIN RESULTS: We compared the abilities of a control and an intervention group of primary care residents, and a group of dermatologists to diagnose and make evaluation plans for six categories of skin lesions including three types of skin cancer-malignant melanoma, squamous cell carcinoma, and basal cell carcinoma. At posttest, both the intervention and control group demonstrated improved performance, with the intervention group revealing significantly larger gains. The intervention group showed greater improvement than the control group across all six diagnostic categories (a gain of 13 percentage points vs 5, p < .05), and in evaluation planning for malignant melanoma (a gain of 46 percentage points vs 36, p < .05) and squamous cell carcinoma (a gain of 42 percentage points vs 21, p < .01). The intervention group performed as well as the dermatologists on five of the six skin cancer diagnosis and evaluation planning scores with the exception of the diagnosis of basal cell carcinoma. CONCLUSIONS: Primary care residents can diagnose and make evaluation plans for cancerous skin lesions, including malignant melanoma, at a level equivalent to that of dermatologists if they receive relevant, targeted education.

Clinical Competence↗
PubMed1998

Ratings of perceived exertion (RPE) during cycling exercises at constant power output.

The purpose of the present investigation was to study the overall rating of perceived exertion (RPEov) according to the 6-20 scale proposed by Borg (1970) and muscular RPE (RPEmu) in exercises at constant load. The relationship between RPE and heart rate for three different loads was studied during exhausting exercises in 10 participants. Whether the drift of RPE during a 20 min exercise at constant load could be an index of the endurance time during long-lasting exercises at constant load was also investigated. At 1-week intervals, the participants performed cycling exercises up to exhaustion at 60, 73, and 86% maximal aerobic power (MAP) measured during an incremental test. Heart rate, RPEov, RPEmu and exhaustion time (tlim) were measured. The upward shift of the HRmax-RPE regressions was significant between 86, 73 and 60% MAP (p < 0.001) for RPEov and RPEmu. This result suggests that the equation HR = 10 x RPE proposed by Borg (1973) for incremental exercise is not valid for long-lasting exercise at constant load until exhaustion because the heart rate corresponding to a given RPE depends on load and time. Mean RPE increased linearly with time up to exhaustion. Unexpectedly, the relationships between RPEmu or RPEov and percentage of exhaustion time were similar for exercises at 60 and 73% MAP although the exhaustion times were very different (79.40 +/- 30.64 min versus 36.19 +/- 15.99 min, respectively) (p < 0.001). Consequently, it is likely that RPE was a subjective estimation of the hardness of exercise rather than the intensity of exercise. The RPE pattern at the beginning of long-lasting exercises at constant load (60 and 73% MAP) cannot be considered as a sensitive predictor of the point of self-imposed exhaustion for individuals. Indeed, the errors in the estimation of exhaustion time from extrapolation of RPE at the beginning of exercise were very large. Moreover, at 60% MAP, a steady-state in RPE was observed during 20 min in five subjects whose tlim were not longer than tlim of the other subjects. In addition, the data of the present study indicate that RPEmu could be more useful than RPEov in cycling.

Adult↗
PubMed1998

Isolated right-sided Bartonella quintana endocarditis in an immunocompetent adult.

Bartonella quintana is a recently recognized cause of culture-negative left-sided endocarditis. We report a case of isolated tricuspid endocarditis caused by B. quintana in a 65-year-old alcoholic man, who also had immune-complex glomerulonephritis. B. quintana was established as the cause of the endocarditis based on serological tests and on failure of extensive efforts to isolate an alternative organism. The patient improved gradually on antibiotic therapy and did not require surgery. To our knowledge, this is the first report of isolated right-sided endocarditis caused by B. quintana. Although uncommon, Bartonella should be considered in patients with isolated right-sided culture-negative endocarditis.

Aged↗
PubMed1998

Aspergillus pericarditis with tamponade: report of a successfully treated case and review.

We report a case of aspergillus pericarditis with tamponade complicating invasive pulmonary aspergillosis in a patient treated for acute lymphocytic leukemia. Prolonged antifungal therapy and aggressive surgical treatment cured the pericarditis, without relapse, despite the fact that the patient underwent autologous bone marrow transplantation. In a review of 28 other cases of aspergillus pericarditis, we found that this condition usually had occurred in severely immunocompromised patients and was always the result of contiguous dissemination of Aspergillus from the lung or myocardium. Tamponade was present in eight of 29 patients. Aspergillus antigen was detected in the pericardial fluid of all three patients whose fluid specimens were tested. Aspergillus pericarditis was diagnosed before death in 10 of 29 patients, all of whom had established premortem diagnoses of invasive aspergillosis at other sites and had received antifungal therapy. Three of the four survivors received combined medical and aggressive surgical therapies. The performance of echocardiography early during the course of invasive pulmonary aspergillosis, together with intensive combined therapies, might lower the high mortality associated with aspergillus pericarditis.

Adult↗
PubMed1998

Diagnostic accuracy of protected specimen brush and bronchoalveolar lavage in nosocomial pneumonia: impact of previous antimicrobial treatments.

OBJECTIVE: To determine whether the diagnostic accuracy of bronchoscopy samples in patients with suspected ventilator-associated pneumonia is affected by prior antibiotic treatment given for a previous infection, and/or by antibiotic treatment recently started to treat suspected ventilator-associated pneumonia. DESIGN: Study of critically ill patients. SETTING: Intensive care unit in a university hospital. PATIENTS: Sixty-three episodes of suspected ventilator-associated pneumonia were prospectively evaluated. Based on prior antibiotic treatment, three groups were defined: no antibiotic group (no previous antibiotic treatments), n = 12; current antibiotic group (antibiotic treatment initiated >72 hrs earlier), n = 31; and recent antibiotic group (new antibiotic treatment class started within the last 24 hrs), n = 20. INTERVENTIONS: Fiberoptic bronchoscopy with quantitative protected specimen brush cultures, bronchoalveolar lavage cultures, and intracellular organism counts of bronchoalveolar lavage cells. MEASUREMENTS AND MAIN RESULTS: The diagnosis of ventilator-associated pneumonia was made in 35 cases, based on histology (n = 2), cavitation (n = 2), blood cultures (n = 4), or outcome under appropriate antibiotic treatment (n = 27). The discriminative value of the tests, based on the area under the receiver operating characteristic curve, was high (> or =0.85) in both current antibiotic treatment and recent antibiotic treatment patients. Sensitivities for a 5% intracellular organism count of bronchoalveolar lavage cells, a protected specimen brush culture threshold of 10(3) colony-forming units (cfu)/mL, and a bronchoalveolar lavage culture threshold of 10(5) cfu/mL were as follows, respectively, in the three groups: 0.71, 0.88, and 0.71 (no antibiotic treatment group); 0.5, 0.77, and 0.83 (current antibiotic group); and 0.67, 0.40, and 0.38 (recent antibiotic group). Specificity was consistently > or =0.9. In the recent antibiotic group, protected specimen brush and bronchoalveolar lavage cultures had lower sensitivities (p < .05), and the best threshold values for these two tests were 10(2) cfu/mL and 10(3) cfu/mL, respectively. CONCLUSIONS: After recent introduction of an antibiotic treatment for suspected ventilator-associated pneumonia, protected specimen brush and bronchoalveolar lavage culture thresholds must be decreased to maintain good accuracy. In contrast, current antibiotic treatment prescribed for a prior infectious disease does not modify the diagnostic accuracy of protected specimen brush or bronchoalveolar lavage.

Adult↗
PubMed1998

Confirmatory platelet-activating factor receptor antagonist trial in patients with severe gram-negative bacterial sepsis: a phase III, randomized, double-blind, placebo-controlled, multicenter trial. BN 52021 Sepsis Investigator Group.

OBJECTIVE: To determine the efficacy and safety of using natural platelet-activating factor receptor antagonist (PAFra), BN 52021, to treat patients with severe Gram-negative bacterial sepsis. DESIGN: A prospective, randomized, double-blind, placebo-controlled, multicenter clinical trial. SETTING: Fifty-nine academic medical center intensive care units in Europe. PATIENTS: Six hundred nine patients with severe sepsis, suspected to be related to Gram-negative bacterial infection, who received PAFra or placebo. INTERVENTIONS: Patients were randomized to receive either a dose of PAFra (120 mg iv) every 12 hrs over a 4-day period or placebo over a 4-day period. MEASUREMENTS AND MAIN RESULTS: The patients were well matched at study entry for severity of illness and for risk factors known to influence the outcome of sepsis. Among all randomized patients, the 28-day, all-cause mortality rate was 49% (152/308) in the placebo group, and 47% (140/300) in the PAFra group (p=.50). When analyzed on the basis of the previously defined target population, the 28-day, all-cause mortality rate was 50% (115/232) in the placebo group and 44% (94/212) in the PAFra group, yielding a 12% reduction in mortality rate (p=.29). In patients with documented infection involving other organisms, there was no difference between treated and placebo groups. When the outcomes of organ dysfunctions were examined in the overall population and in the documented Gram-negative bacterial infection population, the number of patients who resolved hepatic dysfunction tended to be higher in the treated group than in the placebo group (p=.06). The number of adverse events reported were not different between the two groups. CONCLUSIONS: A 4-day administration of the studied PAFra (BN 52021) failed to demonstrate a statistically significant reduction in the mortality rate of patients with severe sepsis suspected to be related to Gram-negative bacterial infection. If PAFra treatment has any therapeutic activity in severe Gram-negative bacterial sepsis, the incremental benefits are small and will be difficult to demonstrate in a patient population as defined by this clinical trial.

APACHE↗
PubMed1998

Strengthening emergency medicine in Poland: a training and partnership model.

OBJECTIVE: To report a qualitative evaluation of the Partnerships in Health Care/EMS Project between Poland and the United States. The goal of the partnership was to strengthen the emergency medical services (EMS) system in three Polish cities, Krakow, Bialystok, and Lodz. METHODS: The Polish participants were interviewed in Poland approximately eight months after a U.S.-based training program. They were asked to evaluate the effectiveness of the partnership project and discuss their experiences incorporating U.S. emergency medicine (EM) knowledge and technology in the Polish EMS system. RESULTS: The Polish physicians identified three major factors that had the greatest impact on the implementation of U.S. EM knowledge in Poland. These factors were the substantive differences between Polish and U.S. EM knowledge and technology, staffing differences in Polish and U.S. ambulances, and the differing role the EMS system plays in the delivery of primary care in the two countries. CONCLUSIONS: The Polish physicians succeeded in training EM providers in the three cities, thus strengthening clinical skills of EMS providers. They also were able to adapt the principles of U.S. EM that they had learned to fit the specific circumstances that characterize Polish emergency care. As in the United States, the health care system in Poland is inseparable from the social, political, and economic realities of the nation.

Emergency Medical Services↗
PubMed1998

Comparison of strategies using cefpirome and ceftazidime for empiric treatment of pneumonia in intensive care patients. The Cefpirome Pneumonia Study Group.

In an international, multicenter, open-label, randomized comparative study, adult patients in intensive care units were enrolled to receive cefpirome intravenously at 2 g twice daily or ceftazidime intravenously at 2 g three times daily for the empiric treatment of pneumonia. Randomization was performed after a double stratification according to the investigator's initial choice of monotherapy or combination therapy and then on the basis of the severity of disease. The primary endpoint was the clinical response at the end of treatment in the intent-to-treat population. Data for all patients were reviewed by a blinded observer. Of the 400 enrolled patients, 201 received cefpirome (monotherapy, 56%) and 199 received ceftazidime (monotherapy, 51%). Pneumonia was hospital acquired for 75% of the patients. Clinical failures rates were 34 versus 36% (odds ratio = 0.922; upper bound of 90% confidence interval = 1.301) in the intent-to-treat analysis for cefpirome and ceftazidime, respectively. For the cefpirome and ceftazidime groups, there were 35 versus 30% clinical failures among monotherapy-stratified patients, respectively, and 34 versus 42% clinical failures among combination therapy-stratified patients, respectively. The rates of clinical failures in the per-protocol analysis were 38 and 42%, respectively. In the population of patients evaluable for bacteriologic efficacy, eradication or presumed eradication was obtained for 71% (172 of 241) and 70% (162 of 230) of the pathogens isolated from the patients receiving cefpirome and ceftazidime, respectively. The mortality rates within 2 weeks after the end of treatment were similar (cefpirome group, 31%; ceftazidime group, 26%), as were the percentages of patients with at least one treatment-related adverse event (17 and 19%, respectively). An empiric treatment strategy with cefpirome at 2 g twice daily is equivalent in terms of efficacy and tolerance to ceftazidime at 2 g three times daily for the treatment of pneumonia in patients in intensive care units.

Adult↗
PubMed1998

Predictors of short- and long-term survival in HIV-infected patients admitted to the ICU.

STUDY OBJECTIVES: To evaluate the prognosis of HIV-infected patients admitted to ICUs and to identify factors predictive of short- and long-term survival. DESIGN: A prospective study from January 1, 1990, to December 31, 1992, including all consecutive HIV-infected patients admitted to our ICU for the first time. ICU survivors were followed up until January 1, 1994. SETTING: An 18-bed infectious diseases ICU in a 1,300-bed university hospital in Paris. PATIENTS: Four hundred twenty-one HIV-related admissions were recorded during the study period (33.5% of 1,258 admissions to ICU); 354 HIV-infected patients were first ICU admissions and were analyzed. MEASUREMENTS AND RESULTS: Predictive factors on univariate and multivariate analyses (logistic regression and Cox model) for short- and long-term mortality were performed. Respiratory failure was the main cause of admission (49.2%), followed by neurologic disorders (26.8%), sepsis (10.2%), heart failure (4.5%), and miscellaneous disorders (9.3%). For these groups, in-ICU and in-hospital mortality rates were as follows: 16.7% and 33.9%; 23.2% and 41.1%; 38.9% and 58.3%; 25% and 68.8%; and 12.1% and 24.2%, respectively. In-ICU and in-hospital mortality rates were significantly different across the groups (p=0.026 and 0.002, respectively). Multivariate analysis showed that the in-hospital outcome was significantly associated with functional status (p=0.05), time since AIDS diagnosis (p=0.04), HIV disease stage (0.016), simplified acute physiology score (SAPS I) (p=0.06), need for mechanical ventilation (p<0.000001), and its duration (p=0.0001). In the 281 patients who were discharged alive from the ICU, cumulative survival rates were 51%+/-38% at 6 months, 28%+/-38% at 12 months, and 18%+/-30% at 24 months. Median and crude mean+/-SD survival times were 199 days and 316+/-343 days. Multivariate analysis showed that the long-term outcome was significantly associated with functional status (p=0.000001), weight loss (p=0.00001), the CD4 count (p=0.00001), the HIV disease stage (p=0.01), the duration of AIDS (p=0.001), the admission cause group (p=0.03), and the SAPS I at admission (p=0.00001). CONCLUSIONS: The short-term (in-ICU and in-hospital) outcome of HIV-infected patients was mainly related to the severity of the acute illness (SAPS I, cause of admission, need for and duration of mechanical ventilation), and to the preadmission health status, based on functional status and weight loss. Some of these parameters, in particular the SAPS I and preadmission health status, also influenced the long-term outcome. Whereas HIV-related variables had little impact on the in-ICU outcome, they were closely related with the in-hospital outcome and even more strikingly with the long-term outcome. Thus, the life expectancy of HIV-infected patients, which depends primarily on the natural history of the HIV infection, is the most powerful determinant of the long-term prognosis. Our results confirm that ICU support for HIV-infected patients should not be considered futile.

APACHE↗
PubMed1998

US family physicians' experiences with practice guidelines.

BACKGROUND: Practice guidelines were developed to improve medical outcomes and cost-effectiveness. The experiences of family physicians, who may need to use multiple guidelines in their practices, are crucial for effective development and implementation of practice guidelines. We surveyed a national sample of US family physicians about factors that affect their adoption and use of practice guidelines. METHODS: We mailed a structured survey to a national random sample of 400 family physician members of the American Academy of Family Physicians. RESULTS: The response rate was 51%. Most respondents (69%) reported a positive attitude about practice guidelines, but only 44% reported using any guidelines. More younger physicians thought that guidelines could be useful tools. Most preferred guidelines that could be modified (87%) and that were no longer than two pages. Only 27% of respondents knew where to locate a guideline on a particular topic. Forty-three percent of respondents reported that it would be useful if guidelines were a component of an electronic medical record. CONCLUSIONS: If guidelines are to be used by practicing family physicians, a generalist perspective needs to be considered in future guideline development and implementation. Younger physicians had more positive attitudes toward guidelines.

Adult↗
PubMed1998

Residents find clinical practice guidelines valuable as educational and clinical tools.

BACKGROUND AND OBJECTIVES: Information regarding clinical practice guideline (CPG) use in residency education is limited. We surveyed a regional population of family practice residents to determine use, attitudes, and curricular needs for practice guidelines. METHODS: A written survey was developed that measured residents' exposure to, frequency of use, attitudes, access, and knowledge about use of CPGs. The survey was mailed to 114 family practice residents. RESULTS: The response rate was 75%. The most frequently seen guidelines were immunization schedules, cancer screening, hyperlipidemia, and hypertension management. The residents reported positive attitudes toward CPGs; 75% thought CPGs were easy to use, 80% thought they improved their efficiency, 78% thought they improved their residency education, and 75% thought they improved patient care. Barriers to effective use of practice guidelines were also identified; 20% knew where to find guidelines in their clinic, 35% had faculty modeling, and 22% knew how to evaluate the validity of a guideline. Eighty-nine percent of respondents desired instruction on CPG use and interpretation. CONCLUSIONS: The surveyed family practice residents have similar usage rates for CPGs as the literature reports for practicing physicians, but residents report more positive attitudes. Barriers that prevent effective use of CPGs in training environments include lack of critical appraisal abilities and faculty role modeling.

Curriculum↗
PubMed1998

Organochlorine compounds (DDE and PCB) in plasma and breast cyst fluid of women with benign breast disease.

The organochlorines, dichloro-diphenyl-trichloroethane and polychlorinated biphenyl (PCB) are pervasive environmental contaminants. Results from previous studies have been conflicting regarding the relationship between the internal dose of these organochlorine residues and breast cancer risk. To determine whether these compounds are present in breast cyst fluids and whether cyst fluid and plasma concentrations are correlated, we analyzed organochlorines in paired cyst fluid and plasma samples from 24 subjects using gas chromatography and electron capture detection. All but one of the women had a history of multiple cysts, suggesting that they were at elevated risk for future breast cancer. DDE (a metabolite of dichloro-diphenyl-trichloroethane) was present in 22 of the cyst samples and PCB was detected in 19 of the cyst samples. Organochlorine levels were more concentrated in the plasma than in breast cyst fluids. Levels of DDE in plasma were significantly correlated with those in cyst fluid (r = 0.73; P < 0.001); in contrast to PCB levels in cyst and plasma (r = 0.37; P = 0.12). Congener specific analysis of the PCBs showed that some individual congeners were preferentially excluded from or concentrated in the cyst fluid. To our knowledge, this study is the first to demonstrate that PCB and DDE are present in cyst fluids and thus in contact with the ductal epithelium of the breast. These results support the use of plasma DDE as a proxy for DDE in the target tissue in research on the role of environmental factors in breast cancer.

Adult↗
PubMed1998

X-twi is expressed prior to gastrulation in presumptive neurectodermal and mesodermal cells in dorsalized and ventralized Xenopus laevis embryos.

Early X-twi expression has been now investigated from egg laying to the early neurulation stages in Xenopus embryos, using both in situ hydridization and the more sensitive techniques of RT-PCR. We show that in unfertilized eggs, a decreasing gradient of X-twi transcript distribution is observed from animal to vegetative caps. X-twi RNA can be weakly detected at stages prior to gastrulation, and with increased intensity from stage 8 onwards. At blastula, X-twi transcripts are located towards the animal pole, and as gastrulation begins, they are detected in the developing axial mesoderm and then they accumulate in the sensorial layer of the neurectoderm, the mesodermal layer and in neural crest cells up to late neurula stages. We show, in addition, that in lithium-chloride- and UV-treated Xenopus embryos (that are respectively both "anteriorized/dorsalized" and in "posteriorized/ventralized"), X-twi RNA is detected in cells in similar positions to those that express X-twi in normal embryos. As a whole, our results show that X-twi is expressed even when regionalization of the mesoderm is disturbed and raises the question of a putative function of X-twi prior to gastrulation.

Animals↗