Cystic fibrosis: making a correct and early diagnosis.

Cystic fibrosis is detected with increasing frequency in older children, adolescents, and even young adults. The quality of life and longevity in patients with cystic fibrosis is more favorable the earlier a diagnosis is made and a therapeutic regimen begun. This report presents and reviews five cases in chich the diagnosis of cystic fibrosis was made after the age of six years. Emphasis is placed on the variability of presenting signs and symptoms and the problems that can arise in confirming a suspected diagnosis of cystic fibrosis.

Characterization of an inductively coupled plasma with xylene solutions introduced as monodisperse aerosols.

The optimum operating parameters of the inductively coupled plasma (ICP) with organic solvents are different from those with aqueous solutions. With organic solvents, the ICP is operated at higher power to overcome plasma cooling due to the organic solvent, and aerosol desolvation is necessary in order to reduce solvent load into the plasma. The monodisperse dried microparticulate injector (MDMI) offers the possibility of controlling solvent load by controlling the frequency with which droplets are introduced into the plasma. A test solution that contained 0.5 mg/L Ba in xylene was used to study the influence of MDMI operating parameters on the behavior of the ICP with an organic solvent. The spatial and temporal distribution of the solvent in the ICP was determined for different droplet production frequencies and MDMI oven temperatures, and the optimum operating conditions were established. The best detection limit for Ba in xylene was 1.5 ng/mL, or 0.16 pg (in 200 droplets).

The value of routine preoperative chest roentgenograms in infants and children.

The charts and routine preoperative roentgenograms of 350 children admitted for elective pediatric surgery were analyzed to evaluate the clinical importance of routine preoperative chest roentgenograms. This analysis, and a review of the literature, should indicate that routine preoperative roentgenograms for elective pediatric surgery are unnecessary. Indications for selected preoperative roentgenograms based on patients' history and clinical findings are enumerated.

Experimental demonstration of a Raman scattering detector based on laser-enhanced ionization.

We report what is to our knowledge the first experimental demonstration of detection of Raman photons by means of laser-enhanced ionization of magnesium atoms in an air-acetylene flame. A frequency-doubled dye laser was directed into a cell containing carbon tetrachloride. The resulting Stokes Raman photons were transferred into the flame, where they excited the magnesium atomic vapor into the 3p(1)P(1) state. The excited atoms were then pumped by another laser into the 5d(1)D(2) state, from which efficient collisional ionization occurred. We estimate a quantum efficiency of approximately 50% for the detector.

Medical futility. Committee on Bioethical Issues of the Medical Society of the State of New York.

The term futile is used in many different ways. It is therefore difficult to decide whether a procedure or treatment such as CPR or hemodialysis or blood transfusion would be futile in a given case. The AMA's guidelines on the appropriate use of DNR orders state that DNR decisions should be made openly. Institutions should have policies and physicians should elicit the patient's preferences about CPR. For physicians, the question is no longer whether we should discuss DNR orders with our patients; instead, the issue is how to do so with compassion and caring. Physicians should share with patients their judgment about what medicine can and cannot do. Then physicians must "make decisions about when to withhold or limit resuscitation openly" in honest and trusting conversation between doctor and patient. Often CPR is an exercise in futility. The medical profession should be vested with the authority to make futility decisions if they are the product of open discussion and shared deliberation between physician and patient, family, or surrogate. Rationing, triage, and medical futility in relation to AIDS patients require careful deliberation and consideration. What was considered medically futile five years ago for an AIDS patient may be appropriate care nowadays. The need for appropriate use or non-use of life-sustaining therapy for the elderly, the terminally ill, patients with AIDS and other incurable illnesses is evident to patients, health care providers, policy makers, and the public. CPR should only be administered if it is expected to confer lasting benefit to the patient. However, if 10% of elderly patients benefit from CPR in the case of out-of-hospital cardiac arrest, how can one consider this procedure futile? Although communication between physician and patient about difficult treatment limitation decisions has markedly improved in recent years, it remains a problem, largely because open dialogue with patients and families about futility is a demanding emotional and intellectual task. The medical profession is charged with setting standards for the proper implementation of judgments regarding futility.(ABSTRACT TRUNCATED AT 250 WORDS)