Synthesis of two biologically active fluorescent probes of thymopentin

This study reports on the synthesis of two fluorescent analogues of thymopentin (TP-5; Arg-Lys-Asp-Val-Tyr). A fluorescein isothiocyanate labeled analogue (FITC-TP-5) and a stilbene isothiocyanate labeled analogue (SITS-TP-5) were extensively purified by ion-exchange and gel filtration chromatography. Characterization of the coupling site through amino acid analysis, dansylation and N-terminal cleavage of the fluorescent amino acid yielded results which indicated that both were mono-labeled analogues derivatized at the N-terminal. These analogues were shown to be TP-5-like in nature by their ability to induce the expression of the Thy 1.2 surface marker on nude mouse prothymocytes in both in vivo and in vitro assays. In addition, these analogues were able to inhibit the specific binding of radiolabeled TP-5 to human lymphocytes. Initial studies describing the interaction of FITC-TP-5 with human lymphocytes are shown.     

Fish and Amphibian Embryos -- A Model System for Evaluating Teratogenicity

Fish and Amphibian Embryos—A Model System for EvaluatingTeratogenicity. Birge, W.J., Black, J.A., Westerman, A.G. andRamey, B.A. (1983). Fundam. Appl. Toxicol. 3: 237–242.Developmental stages of fish and amphibians were used to evaluatereproductive impairments produced by environmental contaminants.Using static-renewal and flow-through procedures, exposure wasinitiated at, or soon after, fertilization and maintained through4 days posthatching. Trace concentrations of many environmentaltoxicants produced high frequencies of mortality and teratogenesis.When developmental stages of the trout were exposed to inorganicmercury, 10% control-adjusted mortality was observed at 1 µg/Land frequencies of terata in hatched populations ranged from8% to 43% for exposure concentrations of 2 to 25 µg/L-In similar tests with the narrow-mouthed toad, 45% mortalityoccurred when mercury was administered at 1 µg/L; frequenciesof teratogenesis ranged from 8% to 17% at exposure concentrationsof 1 to 5 µg/L; and complete mortality occurred at 7 µg/L.Boron-induced teratogenesis in trout ranged from 5% at 1 µg/Lto 51% at higher exposure levels. When catfish embryos wereexposed to atrazine at 0.06, 4.8, and 46.7 mg/L, terata appearedin surviving populations at frequencies of 4%, 69%, and 100%,respectively. Fish and amphibian developmental stages constitutesimple and effective models for 1) investigating mechanismsof teratogenesis, 2) evaluating the impact of environmentaltoxicants on aquatic biota, and 3) identifying environmentalteratogens which may be of concern to human health.     

Limitations of the Countershock Dose Response: A Study of Transthoracic Current

Dose response assessment of Countershock efficacy has been widely determined with respect to energy but not current. The purpose of this study was to examine the utility of the dose response method in a current-based model of trunsthoracic defibrillalion (penlobarbital anesthetized dogs, n = 8). Ventricular fibrillation induction lasting 15 seconds was separated by 5-minute intervals. Current defibrillation threshold (DFT: the lowest current that successfully defibrillated) was determined by decreasing current on successive trials. Energy DFT equaled the energy value of the corresponding current DFT. Subsequent data were expressed in normalized terms with each DFT assigned a normalized value of 1.00. Three shocks were delivered in random order at each of seven normalized current nodes (total of 21 shocks); 0.55, 0.70, 0.85, 1.00, 1.15, 1.30, and 2.00 × DFT (early testing). Randomization was repeated, and a second set of 21 trials were performed (late testing). Composite plots were made relating normalized current and energy to the percent successful defibrillation. The dose response expressed in normalized energy demonstrated an overall shift to the left compared to current. The difference was significant at every node value below the estimated DFT. Ninety percent of successful trials with respect to current and energy occurred at or above 0.85 DFT and 0.55 DFT, respectively. Significant changes in impedance occurred between early testing (60 ± 6 ohms) and late testing (47 ± 5 ohms), n = 8, mean ± SD. Current, compared to energy, is a more accurate parameter in the dose response assessment of transfhoracic defibrillation. This phenomenon is largely secondary to a time-dependent fall in impedance that results in lower delivered voltage and energy for a fixed delivered current. Energy should not be used as a parameter of Countershock efficacy.     

Economic comparison of two strategies of oral cancer screening

Cancer is an important public health problem and new strategiesare needed for its prevention and control. Due to socioeconomicconstraints, a lack of adequate health care infrastructure andother competing health priorities in Trivandrum, there is apressing need to evaluate locally feasible and cost-effectivecancer control strategies. The Regional Cancer Centre, Thiruvananthapuram(RCCT), therefore developed and tested two innovative strategies.The first method used the mass media, the second trained unemployedyouth to carry out the initial screening process. Economic evaluationof both strategies was undertaken which showed that screeningusing young volunteers is more cost-effective, since more earlycancers and pre-cancers can be detected through this method.Screening using the mass media only, was found to be 4–9times more expensive in terms of costs per unit of outcome,than using trained volunteers. We therefore recommend the useof trained volunteers in oral cancer detection camps.     

Continuous positive pressure ventilation in children with bronchopneumonia

The application of a small end-expiratory pressure of 5 cmH2O to the assisted ventilation of nineteen children (mean age 19 months) with bronchopneumonia was compared with intermittent positive pressure ventilation. Within 1 h of introducing continuous positive pressure ventilation the alveolar-to-arterial oxygen gradient was reduced in most patients, with an increase in functional residual capacity and a decrease in total pulmonary blood shunt. Physiological dead space was also reduced, a feature not observed in other studies, and the significance of this finding is discussed. The use of continuous positive pressure ventilation in broncho-pulmonary infection was shown to be effective even at small pressures, and can be recommended especially for patients requiring long-term ventilation.     

False-Positive Behavior with the dP/dt Sensing Pacemaker: A Rare Complication of a Physiological Sensor

As with "nonphysiological" devices, sensors that directly measure physiological variables bave the potential to measure unexpected signals and for the physiological parameter being measured to respond in an unexpected manner. We present tbe case of a dP/dt sensing pacing system that functioned normally for 2 months and then developed upper rate behavior due to the sensing of a high frequency artifact on the pressure recording. Our case and others cited reinforce the need for future physiological rate responsive pacemakers to incorporate a second sensor to provide for backup rate response in cases of inappropriate rate response.     

A CLINICAL STUDY OF MALIGNANT MALARIA IN WUHU* A REPORT OF 297 CASES

Wuhu is the center of the rice-growing districts of Anhwei Pro- vince in the Yangtze Valley where benign malaria is endemic in the summer and fall. Malignant malaria, sometimes known as subtertian, tropical, or estivo-autumnal malaria, occurs sporadically. In the late summer of this year, malignant malaria made its appearance with ten or more admissions daily. Over a third of the hospital beds were occupied by the more serious ones, while those who could walk about were treated in the dispensaries and given quinine. OBSERVATION