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A periodically poled LiNb[O.sub.3] (PPLN) crystal waveguide has been used to produce up to 200[micro]W of mid-infrared light around 3081 [cm.sup.-1] with a wide tunability range of ~35 [cm.sup.-1]. Two commercial near-infrared diode lasers at 1.064[micro]m (pump) and 1.583 [micro]m (signal) are mixed in a nonlinear optical crystal to achieve difference frequency generation. The 48 mm long directly-bonded quasi-phase-matched (QPM) PPLN waveguide shows a conversion efficiency of 12.3% [W.sup.-1]. Applications in trace gas detection have been demonstrated for ethene, using multipass absorption coupled with wavelength modulation spectroscopy, and cavity enhanced absorption spectroscopy with a lock-in detection scheme: bandwidth reduced sensitivities Of [[alpha].sub.min] = 8 X [10.sup.-9] and 1.6 x [10.sup.-8] [cm.sup.-1] [Hz.sup.-1/2](2[sigma]), respectively, have been achieved. OCIS codes: 140.2020, 190.4223, 190.4360, 280.1120, 300.1030, 300.6340.

Although there is controversy over the extent to which physicians incorporate research results into clinical practice, the extent to which their attitudes and beliefs affect patient care has rarely been explored. Based on research, the treatment of patients with breast cancer has changed over the past few years, and many women now undergo less radical surgery. However, acceptance of this change in breast cancer treatment has been slow. To test whether this is related to ignorance of the research findings, uncertainty in interpreting the results, or personal and institutional factors, questionnaires were mailed to 970 physicians in Italy; 657 responded. Surgeons had the lowest response rate (60 percent), and cancer specialists (oncologists) had the highest (89 percent). One hundred additional responses were obtained by telephone. The questionnaire described two breast cancer cases, which differed in regard to the patients' ages, and the physicians were asked how they would manage them. The results indicated that research findings are not always the most important factor in planning patient care. Nine percent of the doctors always chose radical mastectomy, due to misunderstanding of the literature or refusal to believe it. Their decision was based on beliefs about better outcomes with radical surgery. Physicians choosing limited surgery felt that, if the treatments are equally effective, the less mutilating procedure should be performed. The group of doctors who were between these two extremes consistently favored radical surgery for the older patient. Lack of consideration for the patient's right to share in decision-making seems to be the explanation for this response. Cancer care in Italy is not multidisciplinary, and 40 percent of surgeons favored radical surgery for the older patient, and 11 percent favored it for the younger patient. In countries where the care of patients with cancer is multidisciplinary, the approaches of other specialists has forced surgeons to change how they treat patients. It will be interesting to see how physicians' attitudes about patients' rights to be involved in treatment decisions will affect medical practice in the future. (Consumer Summary produced by Reliance Medical Information, Inc.)

To study whether Halsted mastectomy was used only when properly indicated, a prospective survey was undertaken on the process of care of 985 breast cancer patients seen consecutively at 62 general hospitals in Northern and Central Italy. Overall, 79% of Halsted mastectomies were performed inappropriately. The procedure was less likely to be performed on more educated patients and, other factors considered, on those seen at hospitals with larger volume. We conclude that the measurement of utilization of a surgical procedure for which only a few appropriate indications exist may help identify important relationships between hospital characterstics and quality of surgical care. (Am J Public Health. 1993;83:1761-1764), People with breast cancer who are treated in small hospitals with a low volume of breast cancer patients may be at risk for receiving unnecessary radical procedures. The records of 958 breast cancer patients from 62 general hospitals in Italy were evaluated for appropriateness of care. About 34% of the patients were treated with the Halsted radical mastectomy or complete breast removal. Seventy-nine percent of these procedures were considered inappropriate. More educated people were 50% less likely to undergo a mastectomy. Inappropriate use of radical procedures was closely related to the hospital's size and number of breast cancer patients. Those facilities with one to ten and 11 to 20 breast cancer patients had rates of inappropriate care of 36% and 43% respectively. Those hospitals with 20 or more such patients had a 21% rate. Smaller facilities had a 36% rate compared with larger hospitals with a 24% rate.

Meta-analysis is a method of comparing unrelated research studies and allowing the data to be combined. Often this method leads to better assessment of the risks, causes, and correlation of diseases and conditions. The present study reviews 150 research studies dealing with lung cancer and its treatments. The process of review established that few of the studies were properly designed, executed or reported. Although more recently executed and reported studies were found to be more valid than earlier studies, the overall conclusion of this study is that much lung cancer research is often so flawed and imprecisely reported as to make such meta-analysis impossible. This is particularly distressing because the number of studies, the cost involved, and the potential use of combining 150 studies which included more than 30,000 patients, could have resulted in important insights into the causes and treatment of this significant group of cancers. Perhaps this report will allow future investigators to plan, execute and report in a manner that will allow future trials to be more useful. Journal editors and review boards should also examine the need to exercise better judgment and establish stricter rules for the inclusion of studies., ABSTRACT: A review of 150 published randomized trials on the treatment of lung cancer showed serious methodological drawbacks. Handling of withdrawals (only 7 trials had no dropouts), a priori estimates of sample size (only 9 trials specified the required number of patients), blinding of randomization (only 22 trials had a satisfactory procedure), and information on eligible nonrandomized patients (only 13 studies reported it precisely) were areas of major concern. Although trial quality improved over time both in design/execution (study size estimation and analysis by prognostic factors became more frequent) and reporting (information on patients' characteristics and side effects were more thoroughly reported), their evolution was inconsistent. For non-small-cell lung cancer -- despite the persistent lack of proof of efficacy of any active treatment -- an untreated control arm was prematurely abandoned and a wide variety of tested regimens prevailed even in better-quality studies. Slightly more promising is the picture for small-cell lung cancer, where research indicates somewhat more reliable -- though limited -- progress. While clinical research in lung cancer has contributed little to defining the best standard care, we conclude that its heterogeneity makes it unlikely that quantitative meta-analysis of existing trials will be constructive.