Synchronous Rendezvous for Networks of Marine Robots in Large Scale Ocean Monitoring.

We develop a synchronous rendezvous strategy for a network of minimally actuated mobile sensors or active drifters to monitor a set of Lagrangian Coherent Structure (LCS) bounded regions, each exhibiting gyre-like flows. This paper examines the conditions under which a pair of neighboring agents achieves synchronous rendezvous relying solely on the inherent flow dynamics within each LCS bounded region. The objective is to enable drifters in adjacent LCS bounded regions to rendezvous in a periodic fashion to exchange and fuse sensor data. We propose an agent-level control strategy to regulate the drifter speed in each monitoring region as well as to maximize the time the drifters are connected and able to communicate at every rendezvous. The strategy utilizes minimal actuation to ensure synchronization between neighboring pairs of drifters to ensure periodic rendezvous. The intermittent synchronization policy enables a locally connected network of minimally actuated mobile sensors to converge to a common orbit frequency. Robustness analysis against possible disturbance in practice and simulations are provided to illustrate the results.

In vivo biological response to recombinant interferon-gamma during a phase I dose-response trial in patients with metastatic melanoma.

Interferon-gamma (IFN gamma), as produced by recombinant DNA technology, has shown a wide range of immunomodulatory activity in vitro and in vivo. Clinical studies have attempted to establish a dose-response relationship to define optimal dosage ranges for induction of effector cell function and host response in patients with cancer. We conducted a randomized trial to test the in vivo biologic activity of five daily dosages ranging from 3 to 3,000 micrograms/m2, administered by daily 2-hour bolus injection or by continuous infusion for 14 days. We demonstrate comparable immunobiologic effects of recombinant IFN gamma (rIFN gamma; Biogen, Inc, Cambridge, MA) administered by these two schedules at the various dosages tested, and have defined a relationship of dose to biologic response over this 3-log10 dose range. Oligo 2'5' adenylate synthetase (2'5'As) induction, natural-killer (NK) cell activity, and T-cell subset distribution (heightened T helper/suppressor ratio) showed the most consistent treatment-associated changes and the greatest immunobiologic effects at dosages of 300 to 1,000 micrograms/m2. Mononuclear cell DR and DQ antigen expression showed no consistent dose-related treatment effect. The relevance of the phenotypic, functional, and enzymologic effects observed in this trial to any clinical antitumor effects of IFN gamma in cancer therapy must now be established.

Improved immunoadsorption procedure with anion-exchange bacterial cell columns.

Bacterial cell columns for immunoadsorption were prepared with Streptococcus cells and triethylaminoethyl cellulose (Cellex-T) matrix material as a model system. Good column flow properties and satisfactory retention of the cells were obtained with ratios as high as 2 ml of packed cells/3 g dry weight of cellulose. Anion-exchange fractionation of whole serum by the Cellex-T was prevented by using 0.25 M NaCl in the developing buffer. Antibodies were adsorbed directly from whole serum and recovered in high yield by desorption at pH 2.3. Pre-exposing bacterial cells to formalin and washing them with acetone was necessary to ensure that they remained on the columns. One strain of Streptococcus salivarius (SS 908) was satisfactorily retained on a column only after cells were labeled with fluorescein isothiocyanate and washed with acetone. The means by which Cellex-T retains bacterial cells appears to be a combination of electronic attraction and physical entrapment.

The antinociceptive effect of intranigral injection of morphine in ketamine- and halothane-anesthetized rats.

Previous studies have shown that morphine, injected into the substantia nigra of rats, had an antinociceptive effect on the tail-flick test. However, due to a transient behavioral stimulant effect of morphine, given intranigrally, valid tail-flick latencies cannot be obtained prior to 30 min after the injection into the nigra. In order to examine the effect of morphine (5-20 micrograms), injected into the nigra, on the nociceptive tail-flick reflex at earlier times, animals were anesthetized with either halothane or ketamine (100 or 150 mg/kg, i.m.). Halothane blocked the analgesic effect of intranigrally administered morphine. However, a dose-related antinociceptive effect of morphine was observed in ketamine-anesthetized rats. This effect was demonstrable at 5 min after the injection into the nigra animals that received the small dose of ketamine. This finding provides further evidence that the substantia nigra plays an important role in opiate-induced antinociception.

Pentobarbital attenuates the antinociceptive effect of intranigral morphine.

This study was conducted to characterize the temporal relationship between intranigral injection of morphine and the onset of antinociception. The principal findings are: 1) morphine produces antinociception on the hot plate test within three minutes after intranigral injection, 2) the tail flick reflex cannot be measured within the first 30 minutes following intranigral morphine due to motor effects, and 3) pentobarbital suppresses the antinociceptive effect of intranigral morphine on the tail flick test. These findings support the conclusion that the antinociceptive effects of intranigral morphine are mediate by the substantia nigra.

Evidence that physical dependence on morphine is mediated by the ventral midbrain.

Rats were given daily injections of increasing doses of morphine sulfate (40-100 mg/kg, s.c.), for 4 days. Twenty hours after the last injection of morphine, the animals received bilateral injections of naloxone (1-10 micrograms) into the substantia nigra, ventral tegmental area or sites 2 mm rostral, caudal or dorsal to the site in the nigra. Withdrawal signs were monitored for 20 min after the intracerebral injection. Naloxone administered into the nigra in morphine-dependent rats produced dose-dependent significant increases in wet dog shakes, irritability to touch, teeth chattering, diarrhea and locomotion, compared to morphine-dependent animals that received injections of saline into the nigra. The injection of naloxone (3 micrograms) into the ventral tegmental area of morphine-dependent animals, produced irritability to touch and diarrhea, compared to morphine-dependent controls that received saline in this region of the brain. Significant differences in withdrawal signs were observed between morphine-dependent animals, that received injections of naloxone (3 micrograms) into the nigra and those that received naloxone (3 micrograms) into the ventral tegmental area or rostral or caudal sites. No differences between the substantia nigra and the dorsal sites were observed. However, withdrawal symptoms were produced by injections of naloxone into the substantia nigra and ventral tegmental area, even when the guide cannulae were angled to avoid penetration of sites dorsal to these regions of the brain. Naloxone, injected into the ventral midbrain of non-dependent animals, produced no signs of withdrawal. These studies suggest that the ventral midbrain mediates physical dependence on morphine.

The use of intermediate and high purity factor VIII products in the treatment of von Willebrand disease.

Since 1985, viral-attenuated blood products have been available for the treatment of patients with hemophilia. Unfortunately, similar viral-attenuated blood products, enriched for von Willebrand factor (vWF), have not been readily available for the treatment of patients with von Willebrand disease (vWD). In the current study, we examined the clinical efficacy and in vivo properties of two viral-attenuated factor VIII products, Koate-HS and Koate-HP, in the treatment of patients with vWD. Twenty-one (21) infusions were evaluated in 17 different vWD patients (4 with type IA; 8 with Type IIA; 1 with Type IID; 4 with type III). Seven (7) patients received Koate-HS and 12 patients received Koate-HP (2 patients received both products; 1 patient was studied three times). Von Willebrand factor antigen, ristocetin cofactor, bleeding time, and the multimeric composition of vWF were determined pre- and post-infusion. Complete or partial correction of prolonged bleeding times was observed in 2 of the 6 patients tested following treatment with Koate-HS and in 7 out of 11 patients tested following treatment with Koate-HP. Surgery was performed on five of these patients, two of whom were treated with Koate-HS and three of whom were treated with Koate-HP. In the surgical patients, clinical hemostasis was achieved regardless of whether the bleeding time was corrected. We conclude that both Koate-HS and Koate-HP can be utilized successfully in the treatment of patients with vWD in spite of the lack of high molecular weight multimers of vWF in these products.(ABSTRACT TRUNCATED AT 250 WORDS)

Further studies of the effects of intranigral morphine on behavioral responses to noxious stimuli.

Bilateral intranigral microinjection of morphine produces dose-related and naloxone reversible analgesic-like effects on the hot-plate and tail-flick tests. The main objectives of the present studies were to further characterize the analgesic-like effects of intranigral morphine, to determine whether these effects were related to a general impairment of sensory or motor function, and to assess their anatomical specificity. The principal findings are: (1) intranigral morphine (10 micrograms) suppresses pain-related behavior without altering responses to a variety of non-noxious auditory, visual, and somatic stimuli, and without producing motor impairment; (2) movement of injector needles approximately 1 mm rostral, dorsal, or medial to the active nigral site significantly reduces the analgesic-like effect of morphine on the tail-flick test; and (3) electrolytic lesions confined to the nigra significantly reduced the analgesic-like effect of morphine on the hot-plate test. It is concluded that the analgesic-like effects of intranigral morphine are mediated by the substantia nigra and that these effects are specifically related to pain.

Improved salt fractionation of animal serums for immunofluorescence studies.

With all animal serums studied except rat serum, an improved salt fraction that contained a high percentage of gamma-globulin and little or no albumin could be obtained by using optimal ammonium sulfate concentrations. These concentrations were less than the routinely used half-saturated solutions and different from the sometimes quoted one-third-saturated solutions. These are simple, economical methods for obtaining the antibody-containing globulin fractions from the serums of a variety of animals commonly used as antibody producers for immunofluorescence applications. Fluorescent antibody reagents prepared in this laboratory from serum fractions obtained by these optimal procedures provided conjugates that may be superior to those prepared from fractions obtained with a higher and uniform salt concentration.

Conjugation methods in immunofluorescence.

We have described methods of labeling antibody preparations with FITC, TMRI, and RBI. The degree of labeling with FITC can be precisely controlled by using well-defined conjugation procedures and FITC of a known degree of purity. Our experience shows that relatively high F/P ratios of the order of 20 to 25 mug/mg are desirable for antibacterial conjugates. Many commercial preparations of rhodamine isothiocyanate are of very poor quality and are unsatisfactory for use in conjugate preparation. Therefore, one should analyze the rhodamine isothiocyanate product before preparing immune conjugates. Our experience indicates that very satisfactory conjugates of immune IgG or pure antibody can be prepared with TMRI of about 60% purity by using a dye-protein ratio of 20 mug/mg. The optimal dye-IgG ratio for labeling with RBI appears to be about two times that for labeling with TMRI because of the lower specific absorbance and fluorescence emission of RBI. Rhodamine conjugates may be preferred to FITC conjugates in certain situations where tissue autofluorescence interferes with the observation of the yellow-green emission of FITC. Furthermore, mixed rhodamine and FITC conjugates of different specificity can be used to great advantage in double-staining techniques that allow simultaneous screening for two antigenically different organisms on a single microscope slide.

Physicochemical characterization of direct fluorescent antibody reagents.

When the data from performance and physicochemical studies of conjugates are combined for analysis, the performance data and specific titers show a direct relationship to the physicochemical data (Table 2). These reagents were prepared from the same lot of antiserum. The specific titers are very misleading without the accompanying data (Table 2). The protein concentrations range from 4 to 10 mg/ml, the F/P ratios from 10 to 30, and CASE shows gamma-globulin to constitute 30 to 100% of the protein. CASE also shows the gamma-globulin F/P ratio to be only 10 to 20. Using these data, we calculated the concentrations of the gamma-globulins and normalized their titers to 10 mg/ml. The value of good fractionation procedures for recovering gamma-globulin and the desirability of obtaining optimal F/P ratios are reflected in the adjusted titers. Physicochemical characterization of conjugates identifies superior and deficient reagents and frequently reveals the cause of inadequate performance. In this way it serves as a quide for improving reagent quality.

Optimum immunization of rabbits for Streptococcus mutans antiserum and conjugate production and studies of batch immunoabsorption methods.

By far, the most significant rises in titers were seen with the immunization protocol used in series 6. Conjugates prepared from bleedings on the 33rd day produced exceptionally high titers for type b S mutans, and reasonably high titers for type a were obtained in a short time. A concentrated antigen with Formalin (13.4 ml) was given during a ten-day period followed by a two-week rest period, after which booster doses of either antigen with Formalin or live antigen were given (Fig 1). Based on evaluation of the immunization protocol just described, series 6 resulted in the highest titered reagents, but the data are insufficient to permit recommending that particular schedule without limitations. Our experience in the use of live antigens of S mutans for immunization is limited in that only types b, c, and e have been used in this way. The rabbits survived these injections, but the pathogenicity of other strains and other serotypes has not been determined. In addition, protocols including combined injections of killed and living organisms should be tested further for possible improvement in antibody production. In view of these considerations, our recommendations for production of high titered antiserums for S mutans in rabbits are as follows: -Take a preimmunization bleeding from each rabbit and screen by indirect FA tests with the antigens to be used. -Inject heavy concentrations (40 IU/ml) of Formalin-killed cells, intravenously. -Inject for eight to ten consecutive days, giving increasing doses of antigen ranging from 0.2 to 5.0 ml for a total of 12 to 15 ml. -Rest the rabbits for one week. If you are monitoring the progress of immunization, bleed the rabbits before giving booster injections. -Give booster injections on four consecutive days, giving 0.25, 0.5, 1.0, and 1.5 ml of live antigen that has been washed one time to remove traces of media and adjusted to a concentration of 40 IU/ml. If live antigen is not used, continue to give booster injections with killed antigen, injecting 2.0 ml on each of three consecutive days. -Rest the rabbits for one week and take sufficient blood to produce the trial reagents needed, or exsaguinate the rabbits. Absorption of type a conjugates resulted in the total loss of titer for type a cells. The cross-reactions with type b conjugate were easily eliminated by dilution, with the exception of the cross-reaction with S sanguis JC-43. Bratthall's absorption method eliminated all cross-reactions of the type b conjugate. Absorption of type c conjugate successfully removed the cross-reaction with type e cells; however, the loss of homologous type c titer was so great that this absorption is of limited value. High-titered conjugates for types d and e have been obtained by using batch absorption procedures.

Ankle radiograph utilization after learning a decision rule: a 12-month follow-up.

OBJECTIVE: To test whether the reduction in ankle radiograph ordering was sustained during a 12-month period after a formal trial to introduce the Ottawa ankle rules. METHODS: A before-after clinical trial of ankle radiograph ordering practice was performed in a university-based ED. All 1,884 (947 "during intervention," 937 "postintervention") adults seen with acute ankle injuries during 2 12-month trial periods were evaluated. The behavioral intervention was the teaching of the Ottawa ankle rules and feedback of compliance with the rules during the intervention period. No further education about the ankle rules or feedback regarding compliance occurred during the postintervention year. Physicians were unaware of any postintervention surveillance. The primary outcome was the proportion of eligible patients referred for an ankle radiograph during the intervention and postintervention periods. RESULTS: During the intervention period (January 1-December 31, 1993), the proportion of patients who received an ankle radiograph [609 x-rayed of 947 patients seen (64.3%; 95% CI 61.2-67.4%)] did not differ from the proportion who received an x-ray in the postintervention period (January 1-December 31, 1994) [583 x-rayed of 937 patients seen (62.2%; 95% CI 59.1-65.3%), p = 0.65, power > 0.80 to detect a 10% increase in the radiograph ordering rate]. There was also no difference in the radiograph ordering rate in the first 3 months of the postintervention period compared with the last 3 months of the postintervention period (68.8% vs 64.7%, respectively, p > 0.30). CONCLUSIONS: Compliance with the Ottawa ankle rules was sustained during a 12-month postintervention surveillance period when physicians did not know they were being observed. Physicians will continue to use a simple clinical guideline once it has been learned.

Familial intracranial aneurysms: recurrence risk and accidental aggregation study.

BACKGROUND: The Saguenay-Lac-Saint-Jean (SLSJ) region is a geographically isolated area (population 285,955) located in the Northeastern part of the Province of Quebec, Canada. Using a population-based register, the genealogical reconstruction of 502 individuals with ruptured intracranial aneurysm (RIA) showed a familial aggregation (the presence of aneurysm in two or more first- to third-degree relatives) for 144 (28.7%) of them; this proportion is much higher than reported elsewhere. OBJECTIVE: In order to assess the genetic predisposition to RIA in the SLSJ population, the objective of the present study is to compare familial and non-familial cases and to provide an estimate of the recurrence risk ratio for siblings. RESULTS: The age at the time of rupture, the number of intracranial aneurysms for each patient and the location of RIAs were not statistically different in the familial versus the non-familial group. Of the 3449 siblings, 20 (0.58%) had suffered a RIA. The recurrence risk ratio calculated for siblings (defined as the risk of disease among siblings divided by the estimated population prevalence) is 1.6 (CI 95% 1.0-2.4). In other respects, we observed very large kinships in the SLSJ population, with an average number of siblings of 7.2 (SD +/- 3.4), ranging from 0 to 17 individuals. With such large families and on the basis of chance alone, we expected 31.3% of the patients to have at least one first- to third-degree relative with RIA. CONCLUSION: These data show that siblings of patients with RIA in the SLSJ population have a greater risk of RIA than the general population. Nevertheless, the largest part of the familial occurrence observed in the SLSJ region can be explained by accidental aggregation, due to large kinships. We propose that, in this population, an underlying genetic predisposition must be suspected only when three or more cases of RIA are identified among first- to third-degree relatives.

The validity and reliability of hand-held dynamometry in assessing isometric external rotator performance.

The validity and reliability of hand-held dynamometry and Cybex dynamometry were investigated using maximal isometric contractions of the external rotators of the shoulder in 14 healthy male subjects. Three maximum voluntary contractions were recorded from each subject by a hand-held dynamometer and a Cybex isokinetic dynamometer at two testing sessions approximately 1 week apart. Analysis of variance did not reveal any significant differences between the mean peak torques obtained with either instrument or between days. The intrarater reliability was clearly established for both the hand-held dynamometer (r = 0.986) and Cybex dynamometer (r = 0.993). Within-day correlations between the two instruments accounted for 27% (day 1) and 60% (day 2) of the explainable variance. This suggests that although both techniques produced identical peak torque values and measured the same element of performance-strength, they did so in a slightly different manner. The possible nature of these differences is discussed.J Orthop Sports Phys Ther 1988;10(6):213-217.

[Is pediatrics excluded from pharmaceutical innovation?]. / La pédiatrie, toujours exclue de l'innovation pharmaceutique ?

OBJECTIVE: The development of therapeutic strategies for children depends unequivocally on the commercial launching of drugs with pediatric indications. New therapeutic drugs differ from one country to another, particularly considering children. The objective of this study was to compare access to new drugs by children in France (FR) and Canada (CA). MATERIAL AND METHODS: Retrospective study comparing newly marketed drugs in FR and CA from 1 January to 31 December 2009. Data were collected through independent sources: (HAS, Thériaque, ANSM for FR and CEPMB, BDPP for CA). RESULTS: Respectively, 37 and 30 new drugs were put on the market in 2009 in FR and CA. Among them, 38% (n=14) and 27% (n=8) had a pediatric indication. For 91% (FR) and 95% (CA) of the drugs not indicated for children, no clinical study has been planned to define pediatric indications. All the drugs (100%) with pediatric indications presented dosages based on age or weight, but it should be noted that two drugs had no form adapted to children. Fifty-seven percent of these drugs were first available on the French market and later on the Canadian market, with a median delay of 8.5months. CONCLUSION: This study highlights the obvious lack of pediatric drugs contributing to large prescriptions of off-label drugs for children, with no dosage or adapted pharmaceutical form for this population.