A new oil/membrane approach for integrated sweat sampling and sensing: sample volumes reduced from µL's to nL's and reduction of analyte contamination from skin.

Wearable sweat biosensensing technology has dominantly relied on techniques which place planar-sensors or fluid-capture materials directly onto the skin surface. This 'on-skin' approach can result in sample volumes in the µL regime, due to the roughness of skin and/or due to the presence of hair. Not only does this increase the required sampling time to 10's of minutes or more, but it also increases the time that sweat spends on skin and therefore increases the amount of analyte contamination coming from the skin surface. Reported here is a first demonstration of a new paradigm in sweat sampling and sensing, where sample volumes are reduced from the µL's to nL's regime, and where analyte contamination from skin is reduced or even eliminated. A micro-porous membrane is constructed such that it is porous to sweat only. To complete a working device, first placed onto skin is a cosmetic-grade oil, secondly this membrane, and thirdly the sensors. As a result, spreading of sweat is isolated to only regions above the sweat glands before it reaches the sensors. Best case sampling intervals are on the order of several minutes, and the majority of hydrophilic (low oil solubility) contaminants from the skin surface are blocked. In vitro validation of this new approach is performed with an improved artificial skin including human hair. In vivo tests show strikingly consistent results, and reveal that the oil/membrane is robust enough to even allow horizontal sliding of a sensor.

Expression of genes related to oxidative stress in the mouse brain after exposure to silver-25 nanoparticles.

Nanoparticles are small scale substances (<100 nm) used in biomedical applications, electronics, and energy production. Increased exposure to nanoparticles being produced in large-scale industry facilities elicits concerns for the toxicity of certain classes of nanoparticles. This study evaluated the effects of silver-25 nm (Ag-25) nanoparticles on gene expression in different regions of the mouse brain. Adult-male C57BL/6N mice were administered (i.p.) 100mg/kg, 500 mg/kg or 1,000 mg/kg Ag-25 and sacrificed after 24h. Regions from the brain were rapidly removed and dissected into caudate nucleus, frontal cortex and hippocampus. Total RNA was isolated from each of the three brain regions collected and real-time RT-PCR analysis was performed using Mouse Oxidative Stress and Antioxidant Defense Arrays. Array data revealed the expression of genes varied in the caudate nucleus, frontal cortex and hippocampus of mice when treated with Ag-25. The data suggest that Ag-25 nanoparticles may produce neurotoxicity by generating free radical-induced oxidative stress and by altering gene expression, producing apoptosis and neurotoxicity.

Mass spectra and time-resolved fluorescence spectroscopy of the reaction product of glycine with 1,2-indanedione in methanol.

The reaction products of 1,2-indanedione (a new fluorescent fingerprint reagent) with glycine in methanol, at room temperature have been studied using excitation and emission and time-resolved fluorescence spectroscopy. Gas chromatography-mass spectroscopy (GC/MS) has also been used to determine which compounds are formed. Reaction products were identified using GC/MS as 2-carboxymethyliminoindanone (MW=203 g) and 1,2-di(carboxymethylimino)indane (MW=260 g). Identified compounds show room temperature fluorescence lifetimes of tau(1)=7.69 ns and tau(2)=1.27 ns. It is not clear yet which compound is having fluorescence lifetime of 7.69 ns and which one is showing 1.27 ns.

Diimide-enhanced fingerprint detection with photoluminescent CdS/dendrimer nanocomposites.

The chemical development of latent fingerprints by nanocomposites that involve photoluminescent cadmium sulfide nanoparticle aggregates with Starburst dendrimer is demonstrated. The dendrimer bonds to fingerprint residue via its terminal functional groups. When these are amino groups (generation 4 dendrimer), the binding is enhanced by fingerprint pre-treatment with diimide. The diimide converts carboxylic acid moieties of the fingerprint residue to esters that then react with the dendrimer amino groups to form amide linkages. The cadmium sulfide/generation 4 dendrimer development of fingerprints is enhanced by elevated temperature also. Finally, fingerprint development with carboxylate-functionalized cadmium sulfide/generation 3.5 dendrimer nanocomposites is examined. Here, diimide treatment of the dendrimer itself aids the subsequent fingerprint labeling, which involves amino acid of the figerprint residue. Nanocomposite fingerprint detection is compatible with time-resolved imaging for background fluorescence elimination.

Adaptation and survival of surface-deprived red blood cells in mice.

The consequences of lost membrane area for long-term erythrocyte survival in the circulation were investigated. Mouse red blood cells were treated with lysophosphatidylcholine to reduce membrane area, labeled fluorescently, reinfused into recipient mice, and then sampled periodically for 35 days. The circulating fraction of the modified cells decreased on an approximately exponential time course, with time constants ranging from 2 to 14 days. The ratio of volume to surface area of the surviving cells, measured using micropipettes, decreased rapidly over the first 5 days after infusion to within 5% of normal. This occurred by both preferential removal of the most spherical cells and modification of others, possibly due to membrane stress developed during transient trapping of cells in the microvasculature. After 5 days, the cell area decreased with time in the circulation, but the ratio of volume to surface area remained essentially constant. These results demonstrate that the ratio of cell volume to surface area is a major determinant of the ability of erythrocytes to circulate properly.

Managing heartburn at the 'base' of the GERD 'iceberg': effervescent ranitidine 150 mg b.d. provides faster and better heartburn relief than antacids.

BACKGROUND: Many individuals with heartburn self-medicate with antacids for relief of their symptoms. AIM: To compare efficacy of effervescent ranitidine to as-needed calcium carbonate antacids in subjects who self-treat heartburn. METHODS: A total of 155 subjects with frequent antacid-responsive heartburn were randomized to receive effervescent ranitidine 150 mg tablets b.d., or as-needed calcium carbonate 750 mg for 12 weeks. Endoscopic oesophagitis severity and mucosal histology were assessed at baseline, and at weeks 6 and 12. Heartburn frequency, severity, and antacid consumption were recorded daily, and quality of life was assessed at baseline, and at weeks 6 and 12. RESULTS: Heartburn frequency and severity were significantly decreased after 1 day of ranitidine (P < 0.02). By week 6, ranitidine had significantly decreased rescue antacid consumption (7.3 tablets, P < 0.001) vs. antacids (14.1 tablets). Endoscopic oesophagitis healing (

Photoluminescent CdS/dendrimer nanocomposites for fingerprint detection.

CdS/dendrimer nanocomposites with a range of concentrations of the photoluminescent semiconductor nanocluster and the dendrimer are prepared in methanol and 1:9 methanol:water solutions. The solutions are utilized for detection of cyanoacrylate ester fumed and unfumed fingerprints on polyethylene and aluminum foil.

Photoluminescent semiconductor nanocrystals for fingerprint detection.

The concept of utilizing photoluminescent semiconductor nanocrystals for latent fingerprint detection, especially in concert with phase-resolved imaging for background fluorescence suppression, is reduced to practice with CdS nanocrystals that are capped with dioctyl sulfosuccinate. The nanocrystals are dissolved in heptane or hexane and are applied in much the same way as staining with fluorescent dye, on articles that have been pre-fumed with cyanoacrylate ester and also on the sticky side of electrical tape without pre-fuming. Since CdS can form a photoluminescent nanocomposite with dendrimers, a feasibility examination of dendrimer tagging of fingerprints has also been conducted.

Lack of effect of intravenous administration on time to respond to azathioprine for steroid-treated Crohn's disease. North American Azathioprine Study Group.

BACKGROUND & AIMS: Azathioprine is effective for Crohn's disease but acts slowly. A loading dose may decrease the time to response. METHODS: A placebo-controlled study was conducted in patients with active Crohn's disease despite prednisone treatment. Patients were randomized to a 36-hour infusion of azathioprine, 40 mg/kg (51 patients), or placebo (45 patients) followed by oral azathioprine, 2 mg/kg, for 16 weeks. Prednisone was tapered over 5 weeks. The primary outcome measure was complete remission at week 8, defined by discontinuation of prednisone and a Crohn's Disease Activity Index of

Long-term safety and efficacy of combination gemfibrozil and HMG-CoA reductase inhibitors for the treatment of mixed lipid disorders.

BACKGROUND: Combinations of gemfibrozil and a 3-hydroxy-3-methylglutaryl (HMG) coenzyme A reductase inhibitor show promise in treating mixed lipid abnormalities. However, concern regarding the risk of myopathy and hepatic toxicity has limited the use of this combination. To determine the long-term safety and efficacy of this combination, we prospectively identified all patients placed on a combination of gemfibrozil and any HMG reductase inhibitor. METHODS: Pravastatin, simvastatin, fluvastatin, lovastatin, or atorvastatin at incremental doses was combined with gemfibrozil (600 mg twice daily). Lipid profiles, creatine kinase levels, and aminotransferase levels were monitored. Two hundred fifty-two patients with established atherosclerosis receiving combination therapy for a mean of 2.36 +/- 1.52 years spanning a total of 593.6 patient-years were monitored. RESULTS: In 148 patients, gemfibrozil was started before an HMG was added. The pretreatment total cholesterol level fell from 222 +/- 34 mg/dL to 181 +/- 26 mg/dL (P <.001) on combination therapy. HDL cholesterol level rose from 30 +/- 5 mg/dL to 36 +/- 7 mg/dL (P <.01), triglyceride level fell from 361 +/- 141 mg/dL to 212 +/- 101 mg/dL (P <.03). The ratio of total cholesterol to HDL fell from 7.6 +/- 1. 7 to 5.3 +/- 1.6 (P <.001). In 104 patients an HMG was begun before gemfibrozil was added. Pretreatment total cholesterol level fell from 246 +/- 54 mg/dL to 192 +/- 40 mg/dL on combination therapy (P <.01). HDL level rose from 33 +/- 9 mg/dL to 38 +/- 9 mg/dL (P <.03) and triglyceride level fell from 314 +/- 183 mg/dL to 183 +/- 93 mg/dL (P <.001). The ratio of total cholesterol to HDL fell from 7.9 +/- 3.6 to 5.2 +/- 1.4 (P <.001). In both groups the lipid profile on combination therapy was significantly better than that obtained on single-agent therapy. One episode of myopathy (0.4%) and one episode of aminotransferase level elevation (0.4%) of greater than 3 times upper limit of normal occurred. Both resolved with cessation of therapy without consequence. CONCLUSIONS: Combinations of gemfibrozil and an HMG, compared with either agent alone, results in improved long-term control of lipid abnormalities in mixed lipid disorders. The low incidence of toxicity permits the use of combination therapy in patients at high risk of atherosclerotic complications.

Coronary stenting for coronary artery disease in a cardiac transplant recipient.

Accelerated coronary artery disease in the transplanted heart remains the leading cause of death in heart transplant recipients. Traditional treatment modalities have generally yielded sub-optimal results. Coronary artery stents are used frequently in the non-transplanted heart to treat coronary artery disease. Only a few cases using this approach in the cardiac transplant recipient have been reported. This report details the use of this modality in a transplant recipient with significant two-vessel coronary artery disease 11 years after orthotopic cardiac transplantation.

Heartburn requiring frequent antacid use may indicate significant illness.

BACKGROUND: Many otherwise healthy individuals with episodic heartburn self-medicate with over-the-counter antacids. We evaluated clinical characteristics of subjects who had never been medically diagnosed as having any upper gastrointestinal tract disorder and who used antacids for symptomatic relief of heartburn. SUBJECTS AND METHODS: Subjects with at least 3 months of frequent heartburn relieved by antacids, and with heartburn on at least 4 of 7 days during the week prior to study entry, had their medical history and gastrointestinal pathological characteristics recorded. Tests included esophagogastroduodenoscopy, esophageal motility and sensitivity studies, and 24-hour pH monitoring. RESULTS: Of 178 subjects screened, 13 were excluded on the basis of other gastrointestinal diseases at baseline, including diffuse esophageal spasm, peptic ulcer disease, dysplastic columnar metaplasia of the esophagus (Barrett's esophagus), and adenocarcinoma. Ten subjects were ineligible because of insufficient baseline heartburn. The remaining 155 eligible subjects had heartburn for an average of 11 years. Forty-seven percent had daily symptoms and 70% described heartburn severity as moderate, even though on endoscopy most (53%) had normal-appearing esophageal mucosa (grade 0 or 1). Esophageal acid sensitivity was present in 86% of subjects. Mean lower esophageal sphincter pressures and esophageal contractile amplitudes were at the lower limits of normal and total esophageal acid contact time was slightly increased. CONCLUSIONS: Chronic heartburn can reflect a wide range of diagnostic findings, including important underlying pathological features, and may warrant a full medical examination to detect such abnormal conditions and to permit selection of appropriate therapy.

Ranitidine versus cimetidine in the healing of erosive esophagitis.

Ranitidine 150 mg twice daily (BID) is an approved therapeutic approach for relieving the symptoms of gastroesophageal reflux disease. Ranitidine 150 mg four times daily (QID) and cimetidine 800 mg BID are indicated for endoscopically diagnosed erosive esophagitis. This 12-week, randomized, multicenter trial involving 696 patients compared ranitidine 150 mg BID and ranitidine 150 mg QID with cimetidine 800 mg BID in healing erosive esophagitis. Healing rates, as determined by endoscopy, at 4, 8, and 12 weeks were comparable with ranitidine 150 mg BID (38%, 56%, and 71%, respectively) and cimetidine 800 mg BID (37%, 52%, and 68%, respectively), as were reductions in heartburn frequency and antacid consumption. However, ranitidine 150 mg QID produced significantly higher healing rates (49%, 67%, and 77%, respectively) and greater reductions in heartburn frequency and antacid consumption than cimetidine 800 mg BID. All treatment regimens were well tolerated. Thus ranitidine 150 mg BID is as effective as cimetidine 800 mg BID, and ranitidine 150 mg QID is more effective than cimetidine 800 mg BID in healing erosive esophagitis and reducing heartburn frequency and antacid consumption.

Ranitidine 300 mg twice daily and 150 mg four-times daily are effective in healing erosive oesophagitis.

BACKGROUND: Ranitidine 150 mg q.d.s. is the currently recommended dosage in the United States for the treatment of erosive oesophagitis. To determine whether a higher dose of ranitidine administered less frequently would also be effective in healing erosive oesophagitis, we compared ranitidine 300 mg b.d. with ranitidine 150 mg q.d.s. in the treatment of erosive oesophagitis. METHODS: This multicentre, double-blind, randomized, placebo-controlled study conducted in the United States compared two dosages of ranitidine in 772 patients with endoscopically diagnosed erosive oesophagitis. Patients were treated with ranitidine 300 mg b.d., ranitidine 150 mg q.d.s. or placebo for up to 12 weeks. Endoscopies were repeated after 4, 8 and 12 weeks of treatment. RESULTS: Ranitidine 300 mg b.d. was significantly more effective than placebo in healing erosive oesophagitis at weeks 8 and 12 (51 vs. 36% and 66 vs. 52%, respectively; P < or = 0.004). Significantly higher healing rates were also achieved with ranitidine 150 mg q.d.s. compared with placebo at 4, 8 and 12 weeks (37 vs. 21%, 62 vs. 36% and 77 vs. 52%, respectively; P < 0.001). Healing rates were significantly higher with ranitidine 150 mg q.d.s. than with ranitidine 300 mg b.d. at all scheduled endoscopies (P < or = 0.041). CONCLUSIONS: Ranitidine 300 mg b.d. is effective in healing erosive oesophagitis and may be appropriate as an alternative dosage regimen to ranitidine 150 mg q.d.s. in some patients with erosive oesophagitis.

Ranitidine is effective therapy for erosive esophagitis.

Two ranitidine dosages were compared for the treatment of erosive esophagitis in a multicenter, double-blind, randomized, parallel-group, placebo-controlled study. Adults with endoscopically verified erosive esophagitis were treated with either ranitidine 150 mg four times daily (n = 106), ranitidine 300 mg four times daily (n = 106), or placebo (n = 116) for up to 12 wk. Patients were also encouraged to adhere to lifestyle modifications (e.g., to elevate the head of bed, etc). Erosive esophagitis healing, determined by endoscopy, was achieved in 69% and 62% of ranitidine-treated patients by 8 wk and in 79% and 74% by 12 wk (150 mg and 300 mg, respectively) compared with 28% of placebo-treated patients by 8 wk and 40% by 12 wk (p < 0.001 ranitidine vs. placebo). Onset of heartburn relief occurred within 24 h of initiating either ranitidine dosage, and relief was maintained throughout the 12-wk study. Both ranitidine dosages displayed safety profiles similar to that of placebo. We conclude that ranitidine 150 mg or 300 mg administered four times daily is effective for healing erosive esophagitis and relieving its symptoms.

Serious soft tissue infections of the head and neck.

The head and neck contain a number of spaces that can be invaded by organisms of the mouth or by spread of cervical osteomyelitis. Infection in these spaces may progress from superficial infection to cellulitis to the formation of an abscess requiring immediate drainage. Spread of infection between spaces depends on anatomic location. Most patients require hospitalization and intravenous antibiotic therapy. Because a deep space infection may be occult, a high index of suspicion is required for diagnosis. Early recognition is necessary to avoid tissue damage, bacteremia or airway compromise. The possibility of deep space infection should be considered in any patient who does not respond to the usual treatment of an abscessed tooth or tonsillitis. This type of infection also should be considered in a toxic patient who has a fever of unknown origin, with or without blood cultures that show anaerobic organisms. Computed tomography or magnetic resonance imaging is usually necessary to locate the infection and to detect suppuration that will be amenable to surgical exploration and drainage.

Essential health education for deployment in underdeveloped countries.

Educating personnel regarding issues related to health and foreign travel has always been an important deployment concern. This article provides general health education guidelines pertinent to any deployment, but especially foreign deployment. The report is intended as a vehicle for initiating the health education process of nonmedical personnel prior to deployment.

Estimation of percent overweight within families.

When height and weight cannot be directly measured percent overweight can be estimated using self-reported height and weight, reports of others for height and weight, and matching of body shape to silhouettes. The present study assessed the relative benefits of each method for estimating percent overweight within families, as well as the potential for using matching of silhouettes for diagnosing obesity. Analysis of the relationship between percent overweight and silhouette ratings showed increases in percent overweight across the silhouettes. Correlations between self- or other-reported and measured percent overweight showed that self-reports correlated very highly with measured reports of percent overweight (r = .97, .96 for parents and children, respectively), but parent reports of their spouses and children percent overweight were lower (r = .87, .87) and child reports of sibling or parent percent overweight were even lower (r = .75, .75). Significant increases in accuracy of diagnosing obesity were observed when the combination of adjusted self-reports and silhouettes were used in comparison to self-reports alone.