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The role of host size, movement, feeding status, color, and species in the visual host evaluation and recognition behavior of the tick parasitoid, Ixodiphagus hookeriHoward was investigated. Freshly emerged female parasitoids were subjected to a choice bioassay, where the test materials were placed in sealed vials and the vials placed in a Petri dish. When presented with A. variegatumlive and mummified nymphs, females examined: larger nymphs significantly longer than smaller nymphs, fed nymphs significantly longer than unfed nymphs, dead and live nymphs for similar lengths of time, and grey live nymphs and yellow-brown and dark brown mummified nymphs for similar lengths of time. The total number of visits to vials containing these test materials were also not significantly different, except there were significantly more visits to yellow-brown mummies when compared to the number of visits to dark brown mummies. When presented with A. variegatum(host) and R. appendiculatus(nonhost) nymphs, the females examined A. variegatumnymphs significantly longer than R. appendiculatusnymphs. The total number of visits to vials containing A. variegatumnymphs were significantly more than the visits to the vials containing R. appendicualtusnymphs. Furthermore, females spent significantly more total examination time per visit on larger and fed A. variegatumnymphs when compared to smaller and unfed nymphs, respectively. Direct and indirect detection were significant when females were presented with fed versus unfed A. variegatumnymphs, grey nymphs versus yellow-brown mummies, and R. appendiculatusversus A. variegatumnymphs. Direct and indirect detection for the rest of the bioassays were not significantly different. Finally, The percentages of females contacting large fed A. variegatumnymphs first were significantly different from those of females contacting small unfed R. appendiculatusnymphs first. The firstcontact percentages for the rest of the bioassays were not significantly different.

It appears advantageous for many non-human animals to store energy body fat extensively and efficiently because their food supply is more labile and less abundant than in their human counterparts. The level of adiposity in many of these species often shows predictable increases and decreases with changes in the season. These cyclic changes in seasonal adiposity in some species are triggered by changes in the photoperiod that are faithfully transduced into a biochemical signal through the nightly secretion of melatonin (MEL) via the pineal gland. Here, we focus primarily on the findings from the most commonly studied species showing seasonal changes in adiposity—Siberian and Syrian hamsters. The data to date are not compelling for a direct effect of MEL on white adipose tissue (WAT) and brown adipose tissue (BAT) despite some recent data to the contrary. Thus far, none of the possible hormonal intermediaries for the effects of MEL on seasonal adiposity appear likely as a mechanism by which MEL affects the photoperiodic control of body fat levels indirectly. We also provide evidence pointing toward the sympathetic nervous system as a likely mediator of the effects of MEL on short day-induced body fat decreases in Siberian hamsters through increases in sympathetic drive on WAT and BAT. We speculate that decreases in the SNS drive to these tissues may underlie the photoperiod-induced seasonal increases in body fat of species such as Syrian hamsters. Clearly, we need to deepen our understanding of seasonal adiposity, although, to our knowledge, this is the only form of environmentally induced changes in body fat where the key elements of its external trigger have been identified and can be traced to and through their transduction into a physiological stimulus that ultimately affects identified responses of white adipocyte physiology and cellularity. Finally, the comparative physiological approach to the study of seasonal adiposity seems likely to continue to yield significant insights into the mechanisms underlying this phenomenon and for understanding obesity and its reversal in general.

Oxygen and copper(II) ion quenching studies were conducted on a model sensor system to elucidate the significant, yet not fully characterized, role of polymer supports in sensor performance. The system consisted of [Ru(Ph2phen)2(4-cyclamCH2(4′-Me)bpy)]Cl2(Ph2phen = 4,7-diphenyl-1,10-phenanthroline; bpy = 2,2′-bipyridine; cyclam = 1,4,8,11-tetraazacyclotetradecane) as the sensor molecule, copper(II) ions as the quenching analyte, and two polymer supports. One polymer used was a cyclic siloxane cross-linked with a hydrophilic poly(ethylene oxide); the other was a ternary polymer with poly(ethylene oxide), poly(dimethylsiloxane), and 2-hydroxyethylmethacrylate. Both polymers contain a hydrophobic binding region for the sensor molecule and a hydrated hydrophilic region for transport of the ions to the sensor. Luminescence intensity and lifetime measurements show the polymer supports to be equally effective at shielding the sensor molecule from oxygen quenching but not copper(II) ion quenching. Unlike oxygen, the copper(II) ions quench the sensor molecule in solution and in the polymer supports through a combination of static and dynamic quenching. The unquenched excited state lifetimes, bimolecular rate constants, and equilibrium constants are presented, and their differences are interpreted to provide information about the local environment of the sensor molecule immobilized in the polymer supports.

A comprehensive study of the binding interactions between ruthenium complexes with multiple binding sites and monomeric and polymeric β-cyclodextrins is presented. A variety of different binding modes involving single and multiple binding arrangements are found. Binding is critically dependent on the geometry of the guest and host and hydrophobicity effects. There is an optimal spacing of the cyclodextrin units in order to exploit the geometry of the multiple attachment points of the guest. On CD binding, the complexes are shielded from oxygen quenching. Quenching can be reduced by from 3 to greater than 10 times compared to the free complex even though only a small portion of the surface of the complex is protected. The greatly enhanced shielding can be attributed to the excitation being localized in the protected region. With the polymeric hosts, the associated linker can also assist in shielding. Implications of these results to polymer supported quenchometric oxygen sensors are discussed.

Stressors, both physical and psychological, can activate the hypothalamic–pituitary–adrenal (HPA) axis, leading to a wide range of physiological responses including increased glucocorticoid release and suppression of immune function. The majority of studies published to date have focused on the effects of physical stressors (e.g., cold exposure, electric shock) on immunity. The present study examined the role of a stressor, social defeat, on humoral immune function of Syrian hamsters (Mesocricetus auratus). Specifically, adult male Syrian hamsters experienced social defeat (i.e., exposure to a dominant animal in that animal's home cage) that was either acute (i.e., a single exposure) or chronic (i.e., daily exposures across 5 days). A control group of animals was placed in a resident's home cage without the resident animal present and did not experience defeat. After the last encounter, blood samples were drawn and animals were subsequently injected with keyhole limpet hemocyanin (KLH). Blood samples were again taken 5 and 10 days postimmunization and serum was analyzed to determine serum cortisol and anti-KLH immunoglobulin G (IgG) concentrations. Cortisol concentrations were elevated in both acutely and chronically defeated hamsters compared with control animals. In contrast, serum IgG concentrations were significantly reduced in both groups of defeated hamsters compared with control animals. Collectively, these results demonstrate that both acute social defeat and chronic social defeat lead to activation of the HPA axis and suppression of humoral immune function. These data suggest that social defeat is an important, ecologically relevant model with which to examine stress-induced immune suppression in rodents.

A new rapid lifetime determination method (RLD) that uses a rectangular excitation is presented. The information from the exciting, as well as the emitting, portion is used to extract decay parameters for a single exponential decay. The lifetime is computed from the ratio of the integrals of the emission during the excitation period and an equal time interval during the decay (Δt). The new square-wave RLD method (SWRLD) shows speed similar to the standard RLD method but without the necessity of matching Δtto the lifetime for precise results. Monte Carlo simulations are used to predict the capabilities of the SWRLD, and the theory is tested with a luminescent terbium complex. The method is particularly applicable to rapid lifetime analysis for high-performance liquid chromatography (HPLC) and for fluorescence microscopy. It lends itself to use with inexpensive square-wave modulated light-emitting diodes (LEDs).

Women of all ages are increasingly seeking facial cosmetic surgery for personal and professional reasons. A wide array of surgical procedures is available to address each woman's specific request. Esthetic facial surgery and cosmetic dentistry may complement each other to provide dramatic results.

Objective:Current prophylaxis for endocarditis in patients undergoing dental procedures consists of oral administration of amoxicillin. There is concern that the risk of anaphylaxis from systemically administered antibiotics might approach the incidence of endocarditis. Emergence of resistance among bacteria is also favored by systemically administered antibiotics. The present study was designed to assess the efficacy of topical amoxicillin given prophylactically as a mouthwash in reducing the incidence of bacteremia after dental extraction. Study Design:Thirty-six outpatients in a dental clinic were randomized in a 3:2:2 ratio to experimental prophylaxis of topical amoxicillin (3 g per mouthwash rinse; 15 patients), standard prophylaxis of oral amoxicillin (3 g in a single dose; 11 patients), or no prophylaxis (10 patients), respectively. Patients were stratified by severity of periodontal disease and number of teeth extracted. Data were analyzed for differences in the incidence of bacteremia by means of the 2-tailed Fisher exact test. Results:Breakthrough bacteremia after dental extraction was observed in 60% (6 of 10 patients) who received topical amoxicillin and in 89% (8 of 9 patients) who received no prophylaxis (P= .30). By comparison, breakthrough bacteremia after dental extraction was observed in 10% (1 of 10 patients) who received standard prophylaxis with oral amoxicillin (60% vs 10%; P= .05). Conclusions:Topical amoxicillin decreased the incidence of bacteremia in comparison with no prophylaxis, but statistical significance was not achieved (P= .30). Topical amoxicillin was significantly less effective than standard prophylaxis with oral amoxicillin in decreasing the incidence of bacteremia after dental extractions. (Oral Surg Oral Med Oral Pathol Oral Radiol Endod 2001;91:162-5)

Many nontropical rodent species display seasonal changes in both physiology and behavior that occur primarily in response to changes in photoperiod. Short-day reductions in reproduction are due, in part, to reductions in gonadal steroid hormones. In addition, gonadal steroids, primarily testosterone (T), have been implicated in aggression in many mammalian species. Some species, however, display increasedaggression in short days despite basal circulating concentrations of T. The goal of the present studies was to test the effects of photoperiod on aggression in male Siberian hamsters (Phodopus sungorus) and to determine the role of T in mediating photoperiodic changes in aggression. In Experiment 1, hamsters were housed in long and short days for either 10 or 20 weeks and aggression was determined using a resident-intruder model. Hamsters housed in short days for 10 weeks underwent gonadal regression and displayed increased aggression compared to long-day-housed animals. Prolonged maintenance in short days (i.e., 20 weeks), however, led to gonadal recrudescence and reduced aggression. In Experiment 2, hamsters were housed in long and short days for 10 weeks. Half of the short-day-housed animals were implanted with capsules containing T whereas the remaining animals received empty capsules. In addition, half of the long-day-housed animals were castrated whereas the remaining animals received sham surgeries. Short-day control hamsters displayed increased aggression compared to either castrated or intact long-day-housed animals. Short-day-housed T treated hamsters, however, did not differ in aggression from long-day-housed animals. Collectively, these results confirm previous findings of increased aggression in short-day-housed hamsters and suggest that short-day-induced increases in aggression are inversely related to gonadal steroid hormones.

The Increasing popularity of all sporting events results in increased potential for injury. Despite helmet, facemask, and mouthguard use, the face often remains and exposed area at risk in many sports. Dentists rehabilitating patients after facial injuries should understand their patients' previous injuries and treatment.

Le CMT représente moins de 5 % des cancers thyroïdiens associant flushs, diarrhées et exceptionnellement des signes cutanés paranéoplasiques de type sclérodermie.

Proposals for the inclusion of permanently submersed materials in soil taxonomic systems have periodically been put forth since some time in the mid 1800s. The proposals were largely conceptual in nature, relying more on subjective reasoning rather than analytical and field data. Advances in computer and global positioning technology, and the continuing development of the discipline of pedology provided the opportunity to examine shallow water estuarine sediments within a pedological framework. Morphological and analytical data from 85 1.5‐ to 2.0‐m profiles from Sinepuxent Bay, Maryland, indicate that the four pedogenic processes of additions, losses, transformations, and transfers outlined in the generalized theory of soil genesis are active in a subaqueous environment. The evidence of pedogenic processes includes the addition of biogenic calcium carbonate (shells), organic fragments, and organic matter; the loss of organic matter and surficial material; the transfer of oxygen through diffusion and bioturbation processes; and the transformation of humic substances and sulfur (sulfidization). The change in the concept of estuarine substrates from sediment to soil has significant ramifications for pedologists, ecologists, estuarine researchers, and government agencies involved in soil resource inventory and estuarine restoration programs. Application of these concepts could help further our understanding of the relationships between subaqueous soil distribution and submersed aquatic vegetation (SAV); clam, scallop, and oyster habitat; and dredge sites with potential acid‐sulfate weathering. This work resulted in a change to the definition of soil in Soil Taxonomyto include subaqueous soils that are capable of or presently support rooted SAV.

The high rate of thrombosis of 1.0-mm polytetrafluoroethylene (PTFE) grafts has limited their use in microvascular surgery. One possible reason for this is the blood-gas interface due to entrapped air in the interstices. The present study examines the effect on patency rates of elimination of this blood-gas interface by high pressurization. Comparing pressurized and nonpressurized grafts in the same animals showed a patency rate of 100 percent at 7 days for treated grafts, while the control (nonpressurized) grafts had all clotted by 1 hour. The implications for microvascular surgery as well as vascular surgery in general are discussed.

While magnetic resonance imaging (MRI) is not a screening examination in the search for metastatic disease, it has already demonstrated its value when performed as a carefully directed study to detect focal hepatic lesions. 1-4In the past 18 months we have encountered nine patients (six men, three women—ages 14-66) with a variety of primary tumors (renal cell carcinoma, two; colon carcinoma, two; hepatocellular carcinoma, two; pancreatic carcinoma, one; pheochromocytoma, one; rhabdomyosarcoma, one) whose MR scans revealed hepatic metastases after normal or nondiagnostic computed tomographic (CT) scans. The lesions were most clearly demonstrated using spin echo (SE) technique with recovery times (TR) of 2.0 seconds and delay times (TE) of 56 msec; metastases usually imaged with greater signal intensity than surrounding liver parenchyma. Lesions were solitary in three patients, multiple in six, and were found in all hepatic lobes without any specific location predominating. Pathologic confirmations of MR diagnoses were available in six of nine patients In two patients, CT scans were of poor technical quality because streak artifacts from surgical clips obscured portions of the liver. In one patient iodinated contrast medium could not be given. In the remaining six patients CT scan quality was acceptable. This report is not a comparison study of the two modalities. We simply present nine patients in whom metastases were not detected by CT for various reasons but were found by MRI using SE technique.

A prospective, controlled, and blinded clinical study was performed on 56 patient volunteers to determine the effects of two independent variables—the Siltex textured inflatable implant and povidone-iodine irrigation—on the incidence of fibrous capsular contracture following retromammary augmentation. Each patient was randomly assigned both textured and smooth implants and povidone-iodine and saline irrigation, so that each patient served as her own control.The Siltex devices experienced an incidence of class III-IV contracture of only 2 percent, as compared with an incidence of 40 percent around the smooth devices. Most patients, however, preferred the smooth devices despite the higher contracture incidence because the Siltex device was more easily palpable. Povidone-iodine did not reduce the final incidence of contracture. It appeared to delay the onset of contracture, but not with statistical significance. (Plast. Reconstr. Surg.93: 123, 1994.)

Nitric oxide (NO) is well established as a neurotransmitter in the central and peripheral nervous systems1. More recently, another gas, carbon monoxide (CO) has also been implicated in neurotransmission. In the nervous system CO is formed by a subtype of heme oxygenase (HO) designated HO2 (ref. 2). HO2 is localized to discrete neuronal populations in the brain resembling localizations of soluble guanylyl cyclase, which is activated by CO (ref. 3). CO may also function in the peripheral autonomic nervous system, in conjunction with NO. The majority of ganglia in the myenteric plexus possess both HO2 and neuronal NO synthase (NOS)4. Defects in myenteric plexus neurotransmission occur both in mice with targeted deletion of genes for HO2 and neuronal NOS (ref. 5). HO2 also occurs in other autonomic ganglia including the petrosal, superior cervical and nodose ganglia4. Neuronal NOS is localized to neurons regulating male reproductive behavior, such as penile erection, and NOS inhibitors prevent erection6. Because of the other parallels between NO and CO, we speculated that CO may play a role in male reproductive behavior. In the present study we describe HO2 localization in neuronal structures regulating copulatory reflexes. Reflex activity of the bulbospongiosus muscle, which mediates ejaculation and ejaculatory behavior, is markedly diminished in mice with targeted deletion of the gene for HO2 (HO2−).

The effects of reproductive condition and exogenous melatonin on immune function were investigated in castrated European starlings, Sturnus vulgaris. Photorefractory and photostimulated starlings exposed to long days were implanted with melatonin or with blank capsules. Photostimulated starlings with blank capsules exhibited reduced splenocyte proliferation in response to the T–cell mitogen, concanavalin A, compared with the other long-day birds. Exogenous melatonin prevented the suppression of immune function by photostimulation. Photorefractory starlings, with or without melatonin implants, exhibited enhanced immune function compared with photostimulated starlings implanted with blanks. This enhancement was not mediated by endogenous melatonin, but appeared to be related to changes in reproductive state. In addition to the traditional costs of reproduction in birds (e.g. raising of young), there may be a cost of the reproductive state of starlings (i.e. whether they are photorefractory or photostimulated). These data are, we believe, the first to indicate a direct effect of reproductive state on immune function that is independent of both photoperiod (i.e. changes in the duration of melatonin secretion) and gonadal steroids.

Richardson ML, Amparo EG, Gillespy T, Helms CA, Demas BE, Genant HK. Theoretical considerations for optimizing intensity differences between primary musculoskeletal tumors and normal tissue with spin-echo magnetic resonance imaging. Invest Radiol 1985;20:492–497.

We reviewed the clinical presentation, management, and outcome of 25 patients with Ogilvie's syndrome (acute colonic pseudoobstruction) at Memorial Sloan-Kettering Cancer Center from 1982 through 1985. All patients had cancer and severe associated medical problems. Abdominal x-rays uniformly showed cecal distension ranging between 9 and 18 cm. Twenty-four of the 25 patients were treated with conservative nonendoscopic management. One patient had an exploratory laparotomy for prophylactic cecostomy after only one day of conservative therapy. Of the 24 patients treated conservatively, 23 (96%) improved by both clinical and radiologic criteria in a mean of 3.0 days. The remaining patient died of multisystem failure not related to the acute colonic pseudoobstruction. Colonoscopic decompression was not attempted in any of the 25 patients. There were no colonic perforations, and there were no pseudoobstruction-related deaths. This study questions the need for early endoscopic or surgical treatment in cancer patients with acute colonic pseudoobstruction.

The phenomenon of fluorescence emission offers a variety of parameters that can be exploited to achieve highly selective chemical analysis.1 Only a small fraction of chemical species are fluorescent, providing inherent selectivity. Limited applicability, a drawback of the selectivity, can often be overcome by using derivatization or indirect methods based on effects such as quenching, complexation, enzymatic catalysis, and immunochemical equilibria

The outgassing characteristics of three classes of Navy hydraulic fluids were investigated to determine the potential toxicity of resulting gasses in ships' atmospheres. They were: 1. Neopentyl polyol ester (MIL-L-23699B); 2. Triaryl phosphate (experimental); 3. Petroleum base hydrocarbons (MIL-L-17331 F). The samples were sequentially exposed to temperatures of 50, 100, 250, and 450°C each for 3 hours, and the types and amounts of the outgassed products were determined. Emissions of carbon monoxide, aldehydes and nitrogen oxides were observed at 250°C for neopentyl polyol ester and at 450°C for triaryl phosphate. Triaryl phosphate also emitted a large amount of phenol-type constituent. The petroleum base hydrocarbon hydraulic fluid emitted carbon monoxide at 250°C and aldehydes at 450°C. It is recommended that additional samples of each of the classes of hydraulic fluids be studied to establish whether or not the observed behavior is typical. This will provide a basis for material modifications/substitutions to reduce potential hazards.

No abstract available for this article.

Oxygen quenching of [Ru(Ph2phen)3]Cl2(Ph2phen = 4,7-diphenyl-1,10-phenanthroline) and pyrene has been studied in a series of polymer networks of Gp-163 (a methacryloxy functional polydimethylsiloxane) co-polymerized with one of several co-monomers: styrene, trimethylsilyl-methylmethacrylate (T3642), vinyl-tris(2-methoxy-ethoxy)silane, or vinyl-tris(trimethylsiloxy)silane. Sensor performance was studied as a function of the polymer composition in order to delineate the important features for satisfactory O2sensor supports. Quenching behavior was examined as a function of polymer structure, including amount and type of co-monomer. This work shows that the earlier two-domain model is too simplistic. The relative affinities of the different domains for the [Ru(Ph2phen)3]Cl2and pyrene and the efficacy of the domains for O2quenching are important; however, subtle changes in microstructure within domains can also strongly affect behavior. In particular, T3642 exhibits excellent structural and good quenching properties with [Ru(Ph2phen)3]Cl2.

Fluorescence methods have been developed for ultra-low-level detection down to the single molecule level. In ultra-low-level analysis, one successful approach to background reduction is to use hydrodynamically focused sample streams coupled with focused laser excitation to reduce detection volumes. However, low-molecular-weight analytes such as fluorescent dyes or fluorescently tagged nucleotides can diffuse radially out of the sample stream before detection, which can cause a significant reduction in the detection efficiency. Diffusional spreading can cause sample stream mixing in multiplexed analyses. Also, axial diffusion can cause misordering of analyte molecules in DNA sequencing at high analysis rates. A new method is presented for reducing diffusion effects by incorporating a high-molecular-weight species that has a strong binding affinity for the analyte (anchor) into the sheath fluid. As the analyte starts to diffuse out of the sample stream, it associates with the anchor and effectively assumes the anchor's molecular weight. This association reduces the analyte's mobility to that of the anchor. Consequently, both radial and axial diffusion are reduced. Further, in favorable cases, this adduct can have significantly increased luminescence yields and photostability compared to the free analyte. Examples of several dye polymer combinations involving electrostatic and other binding modes are given that show the very beneficial effects of this approach. Extension to other systems is described.

A novel sensor for quantifying molecular O2based entirely on solid-state electronics is presented. The sensor is based on the luminescence quenching of tris(4,7-diphenyl-1, 10-phenanthroline)ruthenium(II) ([Ru(dpp)3]2+) by molecular O2. The sensor involves immobilizing the ruthenium complex within a porous sol-gel-processed glass film and casting this film directly onto the surface of a blue quantum-well light-emitting diode (LED). The ruthenium complex is excited by the LED, the [Ru(dpp)3]2+emission is filtered from the excitation with a low-cost acrylic color filter, and the emission is detected with an inexpensive silicon photodiode. The sensor response to gaseous O2and dissolved O2in water is presented. The sensor exhibits fast response times and good reversibility, and detection limits are 0.5%, 0.02%, and 110 ppb, respectively, for O2in the gaseous (linear Stern–Vobner and multi-site Stern–Volmer analysis) and aqueous phase. This sensor provides a cost-effective alternative to traditional electrochemical-based O2sensing and also provides a platform for other optically based sensors.

Hepatic dysfunction can cause a wide variety of alterations in physiologic homeostasis. The interaction of liver disease with perioperative surgical and anesthetic management must be considered by the oral and maxillofacial surgeon in this growing patient population.

We report the case of a 71-year-old man who had interval gangrene of his calf with subsequent vein graft blowout 3 months after undergoing a femoral-to-dorsalis pedis saphenous vein bypass grafting procedure. To provide wound coverage, restore vascular continuity, and preserve functional ambulation, a flow-through radial forearm fasciocutaneous free flap was interposed between cut ends of the bypass graft. Venous drainage of the flap was from the cephalic vein to the popliteal vein. At 1 month after the operation, the patient had complete wound healing and began to ambulate. At 11 months an asymptomatic high-grade stenosis in the distal radial artery segment of the reconstruction was successfully treated with percutaneous angioplasty. After 22 months of follow-up there have been no further complications, and the patient continues to have full, functional ambulation. The radial forearm flow-through free flap allows single-stage restoration of bypass graft continuity and coverage of extensive, complex tissue defects. This technique represents a novel approach to this difficult problem and provides a viable alternative to major limb amputation. (J Vasc Surg 1997;26:711-4.)

A comprehensive list of questions to be used in the evaluating of library security measures.