Highly stable multi-anchored magnetic nanoparticles for optical imaging within biofilms.

Magnetic nanoparticles are the next tool in medical diagnoses and treatment in many different biomedical applications, including magnetic hyperthermia as alternative treatment for cancer and bacterial infections, as well as the disruption of biofilms. The colloidal stability of the magnetic nanoparticles in a biological environment is crucial for efficient delivery. A surface that can be easily modifiable can also improve the delivery and imaging properties of the magnetic nanoparticle by adding targeting and imaging moieties, providing a platform for additional modification. The strategy presented in this work includes multiple nitroDOPA anchors for robust binding to the surface tied to the same polymer backbone as multiple poly(ethylene oxide) chains for steric stability. This approach provides biocompatibility and enhanced stability in fetal bovine serum (FBS) and phosphate buffer saline (PBS). As a proof of concept, these polymer-particles complexes were then modified with a near infrared dye and utilized in characterizing the integration of magnetic nanoparticles in biofilms. The work presented in this manuscript describes the synthesis and characterization of a nontoxic platform for the labeling of near IR-dyes for bioimaging.

A versatile stable platform for multifunctional applications: synthesis of a nitroDOPA-PEO-alkyne scaffold for iron oxide nanoparticles.

Contemporary magnetic nanoparticle composites are individually designed for specific biomedical applications. We describe the syntheses and characterization of a heterobifunctional polyethylene oxide (PEO) using nitroDOPA as a robust anchoring group on one end and an alkyne as the reactive surface for additional application specific modification.

The recent expansion of Pluto's atmosphere.

Stellar occultations--the passing of a relatively nearby body in front of a background star--can be used to probe the atmosphere of the closer body with a spatial resolution of a few kilometres (ref. 1). Such observations can yield the scale height, temperature profile, and other information about the structure of the occulting atmosphere. Occultation data acquired for Pluto's atmosphere in 1988 revealed a nearly isothermal atmosphere above a radius of approximately 1,215 km. Below this level, the data could be interpreted as indicating either an extinction layer or the onset of a large thermal gradient, calling into question the fundamental structure of this atmosphere. Another question is to what extent Pluto's atmosphere might be collapsing as it recedes from the Sun (passing perihelion in 1989 in its 248-year orbital period), owing to the extreme sensitivity of the equilibrium surface pressure to the surface temperature. Here we report observations at a variety of visible and infrared wavelengths of an occultation of a star by Pluto in August 2002. These data reveal evidence for extinction in Pluto's atmosphere and show that it has indeed changed, having expanded rather than collapsed, since 1988.

Olanzapine treatment for post-traumatic stress disorder: an open-label study.

Post-traumatic stress disorder (PTSD) is a common and increasingly diagnosed mental illness. Recent pharmacotherapeutic research on treatments for this condition has focused on antidepressant drugs with serotonergic actions. However, the presence of intrusive, psychotic-like symptoms in a substantial portion of PTSD patients raises the possibility that antipsychotics with serotonergic properties might also prove useful in treating PTSD. We conducted an open-label 8-week study of olanzapine treatment in veterans with combat-induced PTSD. Primary outcome measures in this study were the Clinician Administered PTSD Scale (CAPS) and the Clinical Global Impressions Improvement scale. Secondary outcome measures included the Hamilton Rating Scales for Depression (HRSD) and Anxiety (HRSA). Forty-eight patients enrolled in the study, and 30 completed the 8-week trial. Results of intent-to-treat and completer analyses demonstrated that all outcome measures improved significantly during treatment. Secondary analyses indicate that improvement in the intrusive symptom cluster of the CAPS was independent of improvement on the HRSD and HRSA. In conclusion, the study indicates that olanzapine treatment is useful in alleviating the symptoms of combat-induced PTSD.

Effect of hydrochlorothiazide in pseudohypoaldosteronism with hypercalciuria and severe hyperkalemia.

Severe hyperkalemia resistant to treatment with sodium chloride (NaCl) supplements plus cation exchange resins can be found in pseudohypoaldosteronism type I. In a patient with the multiple target organ variant of this condition, hyperkalemia persisted at dangerous levels (8.5 mmol/l) despite large doses of NaCl (50 mmol/kg per day) and cation exchange resins (6 g/kg per day). Hypercalciuria was also present. The total volume of fluids and supplements required was not tolerated orally. Indomethacin (2 mg/kg per day) and later hydrochlorothiazide (2 mg/kg per day) were tried to further correct imbalance. Plasma potassium (K) and Na levels, the urinary Na/K ratio, transtubular potassium gradient (TTKG), and urinary calcium/creatinine (Ca/Cr) ratio were used to evaluate the effect of hydrochlorothiazide. Under treatment, plasma Na was stable (137-144 mmol/l), K levels decreased from 8.5 to 5 mmol/l, urinary Na/K from 90 to 24, and TTKG increased from 0.3 to 1.8. Ca/Cr decreased from 3.5 to 1.5 mmol/mmol. The dosage of cation exchange resins was decreased, oral fluids were tolerated, and the patient's general condition improved. Hence: hydroclorothiazide can be useful in the treatment of severe hyperkalemia and hypercalciuria of pseudohypoaldosteronism type I.

Further evidence of the relationship between case typicality and diagnostic performance: implications for medical education.

We have produced further evidence demonstrating that DDx performance is a function of a test case's typicality. Medical educators might consider exploring how cognitive scientists have used the typicality assumption to investigate and enhance the instruction and assessment of subjects engaged in other classification tasks. Further substantiation of the applicability and utility of the assumptions making up the abstraction and exemplar theories used to explain DDx performance could serve as the basis for effective and efficient curricular reforms in medical education.

Ulcer recurrence following duodenal ulcer healing with omeprazole, ranitidine, or placebo: a double-blind, multicenter, 6-month study. The Omeprazole Duodenal Ulcer Study Group.

The present study determined whether the rate of relapse of duodenal ulcer was reduced after ulcer healing with omeprazole compared with ranitidine or placebo. It was made up of a double-blind, randomized, controlled multiple-center trial set within the United States. Patients were candidates if their duodenal or pyloric channel ulcer successfully healed in one of two large multicenter U.S. trials; one compared omeprazole, 20 mg once daily, before breakfast with ranitidine, 150 mg twice daily, and the other compared the same dose of omeprazole with placebo. Two hundred forty (73.8%) of the 325 patients with complete ulcer healing within 4 weeks of starting therapy who were eligible to enter the follow-up study were enrolled. There was no intervention. Endoscopic assessment of ulcer status was performed at 2, 4, and 6 months and whenever patients had symptoms thought to represent return of an ulcer. The lifetable relapse rates for duodenal ulcer according to initial ulcer therapy with omeprazole, ranitidine, or placebo were 76.7% [95% confidence interval (CI), 64%-89.3%], 59.8% (95% CI, 47.8-71.7%), and 50.4% (95% CI, 15.7%-85.2%), respectively. These rates were not statistically significantly different. Seventeen percent of recurrent ulcers occurred at a site different from that of the original ulcer. It is concluded that despite the more rapid rate of duodenal ulcer healing with omeprazole therapy, the rate of ulcer relapse appears similar and independent of whether ulcer healing was accelerated with omeprazole or ranitidine.

Famotidine (20 mg) b.d. relieves gastrooesophageal reflux symptoms in patients without erosive oesophagitis. Famotidine/GERD Investigation Group.

Previous clinical trials have evaluated a large number of symptomatic individuals with heartburn. Most studies have documented the need for multiple daily dosing with H2-antagonists to achieve clinical and statistical efficacy for symptom relief. The purpose of this study was to compare the safety profile and efficacy of famotidine oral dosing regimens, 40 mg nocte and 20 mg b.d. with placebo in the relief of symptoms in patients suffering from frequent heartburn found to have endoscopically normal oesophageal mucosa or mild non-erosive oesophagitis. Famotidine (20 mg) b.d. reduced and eventually completely relieved gastro-oesophageal reflux disease symptoms in most patients during the 6-week trial. Global assessment of improvement at 2 and 6 weeks indicated significantly greater improvement with a b.d. treatment regimen than with either a 40 mg nocte or placebo treatment. No statistically significant differences between famotidine and placebo in the number of patients who experienced clinical adverse experiences were noted and no serious adverse events attributable to famotidine occurred. Based upon these findings, patients with gastro-oesophageal reflux symptoms experience good relief of their complaints with twice daily famotidine in standard doses.

Omeprazole versus placebo in duodenal ulcer healing. The United States experience.

The study objective was to study the ulcer healing effects and safety of the proton pump inhibitor, omeprazole, given in a dose of 20 mg once daily before breakfast. The study design was a randomized, double-blind, multicenter comparison of omeprazole and placebo using endoscopy to assess ulcer healing after two or four weeks of therapy. One hundred fifty-three patients with endoscopically documented active duodenal ulcer were studied. One hundred two patients received omeprazole and 51 received placebo. Patients in both groups were similar with regard to age, sex, duration of disease, initial ulcer size, smoking history, and alcohol use. A "per protocol" analysis of healing rates showed a significant advantage for omeprazole (P less than 0.01) at both week 2 (41% vs 13%) and week 4 (75% vs 27%). Concomitant factors (including smoking and ulcer size) did not alter the significance of the differences in healing rates between omeprazole and placebo. Complete relief of day and night pain was more often achieved (P less than 0.01) in the omeprazole group. "All-patients treated" analyses for healing and pain relief gave results similar to the respective "per protocol" analyses. Omeprazole was well tolerated; fewer patients had clinical and laboratory adverse experiences in the omeprazole group than in the placebo group. Fasting serum gastrin levels increased with omeprazole therapy (mean 34.9 to 73.5 pg/ml) but exceeded the normal range (greater than 150 pg/ml) in only 12.3% of patients. Two weeks after therapy was stopped, serum gastrin levels showed a decrease toward baseline but had not yet completely returned to pretreatment levels (mean 49.7 pg/ml).(ABSTRACT TRUNCATED AT 250 WORDS)

Efficacy of once-daily cimetidine in preventing recurrence of duodenal ulcer.

In a prospective multicenter trial, 88 patients with acute duodenal ulcers that were healed with ranitidine were randomly assigned to receive maintenance treatment with either cimetidine 400 mg (n = 45) or placebo (n = 43) at bedtime for six months. Ten percent of the patients experienced moderate or severe pain both during the day and at night while on placebo during the maintenance phase. The average proportion of cimetidine patients experiencing moderate or severe pain during the day or night was 50% and 80% lower than placebo, respectively. Ulcer-like symptoms prompted endoscopy in 44% (19 of 43) of the placebo patients compared with 18% (eight of 45) of patients receiving cimetidine (P = 0.009). At the completion of the maintenance study, cumulative symptomatic ulcer recurrence rates were 28% (12 of 43) for those on placebo compared with 13% (six of 45) for cimetidine patients. The adverse drug effects noted were similar between treatment groups, with no unexpected reactions reported. A low dose of cimetidine (400 mg) at bedtime effectively reduced the incidence of gastrointestinal symptoms that were severe enough to prompt endoscopy as well as the actual recurrence of ulcers in those patients who had responded to initial therapy with ranitidine, but who continued to be at increased risk of reulceration.

The efficacy of cimetidine in the treatment of "resistant" duodenal ulcers.

In a prospective multicenter trial, 43 patients with acute duodenal ulcers unhealed after four weeks of treatment with an H2-receptor antagonist, ranitidine, were switched to treatment with another H2-receptor antagonist, cimetidine. Sixty-eight percent of the unhealed patients were successfully healed; of these patients, 81% were free of daytime pain and 89% were free of nighttime pain. Of those with residual pain, 71% and 50% showed improvement in daytime and nighttime pain severity, respectively. There were no unexpected adverse reactions reported or clinically significant changes in laboratory values measured during the study. It is concluded that cimetidine is highly effective both in healing duodenal ulcers unresponsive to ranitidine therapy and in providing continued relief of daytime and nighttime pain.

The cercal receptor system of the praying mantid, Archimantis brunneriana Sauss. I. Cercal morphology and receptor types.

The cerci of the praying mantid, Archimantis brunneriana Sauss., are paired segmented sensory organs located at the tip of the abdomen. Basally the cercal segments are slightly flattened dorso-ventrally and are fused to such a degree that it is difficult to distinguish them. Distally the segments become progressively more flattened laterally and their boundaries become more obvious. Two types of sensilla are present on the cerci, trichoid sensilla and filiform sensilla. Trichoid hairs are longest on the medial side of the cerci and toward the middle of each segment while they are more uniformly distributed on the distal segments. Filiform sensilla are found at the distal end of each segment except the last and are highly variable in appearance from short and stout to long and thin. They arise from a raised base, have a fluted shaft, and some have a pore at the tip. They are innervated by from one to five dendrites, one of which is always considerably larger than the others. Some of the dendrites continue out into the shaft of the hair. Filiform hairs have fluted shafts and are mounted in a flexible membrane within a cuticular ring in a depression. They are innervated by a single large sensory neuron, the dendrite of which passes across a flattened area on the inner wall of the lumen of the hair. The dendritic sheath forms the lining of the ecdysial canal and is therefore firmly attached to the hair. The dendrite is attached to the sheath by desmosomes distally and is penetrated by projections of the sheath more proximally. A fibrous cap surrounds the dendrite and may hold it in place relative to the hair. The cercal receptor system of Archimantis is compared to those of cockroaches and crickets.

The cercal receptor system of the praying mantid, Archimantis brunneriana Sauss. II. Cercal nerve structure and projection and electrophysiological responses of the individual receptors.

The bilaterally paired cercal nerves of Archimantis brunneriana Sauss. leave the terminal ganglion posteriorly and then turn dorsally through muscles at the rear of the abdomen to enter the cerci, where each splits into two branches; successive branchings occur further distally in each cercus. In the distal nerve branches large axons tend to be grouped together. The cercal nerves are heavily wrapped in glial sheaths. Cobalt backfills of the cercal nerve reveal a projection which enters the ganglion at approximately 30 degrees to the midline and then turns parallel to it. Most of the projection remains ipsilateral but bundles of axons approach or cross the midline in 6-8 places. At the anterior end of the ganglion there are strong projections both laterally and medially. In the posterior half of the ganglion fibers run ventrally to surround two glomeruli and there is a dorsal projection in the anterior half of the ganglion. There is a strong projection anteriorly into the ventral nerve cord. The electrophysiological responses of single cercal receptors to pulses of wind were recorded in the cercal nerve or terminal ganglion. These receptors, presumed to innervate filiform hairs, were then filled with Lucifer Yellow. All had ipsilateral projections. Most receptors showed little adaptation to stimuli as long as 5 seconds.

Dimensional stability of temporary restoratives.

The effects of thermal cycling on the dimensional stability of temporary restoratives were studied. Stability appeared to be affected significantly by water content. On thermal cycling, Cavit showed less linear dimensional change than two cements containing zinc oxide-eugenol and gutta-percha temporary stopping.