Micromachined silicon nitride deformable mirrors for focus control.

We have built a 1000mum-diameter silicon nitride deformable mirror for focus-control applications, using micro-optoelectromechanical systems technology. We achieved variable focal lengths from 36 to 360 mm while maintaining zero primary spherical aberration, using a maximum control voltage of 100 V. Active control of spherical aberration of approximately two waves at 660 nm was demonstrated.

Levofloxacin-induced bilateral Achilles tendonitis.

OBJECTIVE: To report a case of possible levofloxacin-induced bilateral Achilles tendonitis. CASE SUMMARY: An 83-year-old white woman presented to her physician with five days of hemoptysis. She was diagnosed with right lower-lobe pneumonia based on chest X-ray, and levofloxacin 500 mg/d po for 10 days was prescribed. Three days into treatment she began having a variety of adverse effects, including severe nausea, constipation, stomach cramps, and dizziness. Signs of tendonitis began three days after treatment and peaked four days after completion of therapy. Two weeks later, she was treated by her podiatrist with an ankle immobilizer and rest. At her three-week follow-up, she had marked improvement in her pain and bruising; however, her symptoms had not completely resolved. DISCUSSION: Tendonitis and tendon rupture are rare adverse effects of fluoroquinolone antibiotics; there are no reports in the literature of levofloxacin-induced tendonitis. As newer fluoroquinolones become available, the postmarketing studies will become increasingly important to capture the data on rare but serious adverse effects not discovered in the premarketing trials. CONCLUSIONS: To our knowledge, this is the first reported case of tendonitis caused by levofloxacin reported in the literature. Reports have been made, however, to the manufacturer via postmarketing surveillance. As more people are treated with newer fluoroquinolones, the clinical incidence of tendon rupture with these agents may become clearer.

Micromachined scanning confocal optical microscope.

We have constructed a miniature confocal optical microscope for monochromatic imaging that uses single-mode fiber illumination and a two-phase off-axis zone plate objective lens. The scanning mechanism consists of two micromachined silicon torsional scanning mirrors with orthogonal axes of rotation. The objective lens is made of fused silica and has a N.A. of 0.24 at lambda = 0.6328 microm, with a 1.0-mm working distance. The device is side looking, with die dimensions of 1.2 mm x 2.5 mm x 6.5 mm. We have measured 1.0-microm resolution over a 100-microm field of view.

Frequent acquisition of multiple strains of methicillin-resistant Staphylococcus aureus by healthcare workers in an endemic hospital environment.

Methicillin-resistant Staphylococcus aureus (MRSA) has been an endemic nosocomial pathogen at the VA medical center (VAMC) in Providence, Rhode Island since 1981. From 1985 to 1987, more than 30% of all unique S aureus isolates were methicillin resistant. To evaluate the frequency of acquisition of MRSA isolates by healthcare workers, we compared the antimicrobial susceptibility patterns, multilocus enzyme genotypes and plasmid profiles of isolates recovered from nasal and hand cultures from VAMC nurses and house staff on rotation at the VAMC with those of clinical isolates from patients at the VAMC and four other affiliated hospitals. Fifty-six percent of ward nurses cultured (n = 112) were colonized with S aureus, of which 65% was methicillin resistant. Six isolates of MRSA were identified on the initial culturing of house staff (n = 65); 16 MRSA isolates were recovered at the end of a four-week rotation (p less than .02). Phenotypic and genotypic analyses demonstrated that numerous distinct MRSA strains were recovered in the study period. The incidence of MRSA among clinical isolates at the VAMC and affiliated institutions was remarkably constant throughout the three-year study period. Moreover, despite regularly sharing resident physicians, interns and medical students, MRSA isolates were commonly recovered at the other university-affiliated hospitals. Our study failed to reveal evidence of significant interhospital transmission of MRSA isolates by healthcare workers. While healthcare workers may contribute to the dissemination of MRSA within institutions, they appear to be less important in spreading MRSA between institutions.

Tuberculosis makes a comeback. Giving and interpreting the Mantoux test.

Tuberculosis is on the increase in the United States, so physicians would be prudent to renew familiarity with the disease. Physicians should be prepared to administer the Mantoux test correctly and interpret the results according to the specific condition of each patient. Patients with certain diseases (eg, chronic renal failure, lymphoid disorders) are likely to be anergic but are also more likely than other persons to have tuberculosis. In these patients, the goal is to administer the test before they become anergic, so infection can be identified if it occurs. Preventive therapy is useful in some situations (eg, when public health is a factor) and should also be chosen on the basis of the individual patient, weighing the risk of disease against the risk of drug toxicity.