Comparison of the protective effects of three phosphorothioate radioprotectors in the RIF-1 tumor

Three aminoalkyl phosphorothioates, WR-2721, WR-3689, and WR-77913, were compared as radioprotectors of RIF-1 tumors irradiated in vivo and assayed for cell survival in vitro. The protector doses were 50% of the acute drug LD50. The radiation dose modifying factors for the three drugs were nearly equal, ranging from 1.5 to 1.7 at surviving fractions of 0.1 and 0.05. Using biodistribution data obtained with 35S labeled drugs, the uptake in tumors was calculated as micromoles drug per gram of tumor. On this basis, tumor levels of WR-77913 were 4.5-fold those of WR-2721, and WR-3689 uptake was 2.7-fold greater than uptake of WR-2721. Thus, on a molar basis, WR-2721 appears to be the most effective protector, but all three phosphorothioates protect this tumor moderately well. In diffusible substance autoradiographs of 3H WR-3689 labeled tumors, label was generally distributed over cells with no evidence of preferential localization over nuclei.

Effect of naltrexone on apnea of prematurity and on plasma beta-endorphin-like immunoreactivity

Plasma levels of beta-endorphin-like immunoreactivity (beta-ELI) were measured in premature infants with apnea (n = 11) and compared to those in nonapneic controls (n = 9). Naltrexone (1-3 mg/kg) was given to the infants with apnea, 6 of whom were also receiving methylxanthines. Chest wall movements, nasal airflow, transcutaneous PO2 and electrocardiogram were recorded for 4-6 h prior to and for 4-6 h after administration of naltrexone. Samples for beta-ELI were taken prior to and 1 h post naltrexone. beta-ELI levels were significantly higher (p less than 0.007) in infants with apnea of prematurity than in control infants. No significant difference was found in beta-ELI levels before and after naltrexone. Naltrexone did not decrease the incidence of apnea.

Comparison of binding of [3H]misonidazole and [14C]misonidazole in multicell spheroids

Uptake of [2-ring-14C]misonidazole and [3H]misonidazole with tritium in the side chain has been compared in 1-mm EMT-6/UW spheroids using liquid scintillation counting and autoradiography. The uptake of both labeled sensitizers as a function of incubation time was virtually identical. Uptake by the spheroids exceeded levels in the medium by 11/2 to 2 hr and was well modeled as a first-order binding process, with rate constants of 0.00324 hr-1 for 3H and 0.00388 hr-1 for 14C. The similar uptake of the two versions of this sensitizer labeled in different positions suggests that the metabolic actions which allow the drug to bind in hypoxic cells do not principally involve metabolites which separate the number 2 carbon of the imidazole ring from the side chain. The pattern of silver grains in autoradiographs was similar for both labeled sensitizers, with most labeled drug bound in an intermediate zone of cells between the necrotic center and the actively proliferating rim of the spheroids. The superior resolution possible with the tritiated compound showed that both nucleus and cytoplasm in viable looking cells were labeled while pycnotic cells were not labeled.

Enumeration of cytoplasmic mu immunoglobulin positive acute lymphoblastic leukemia cells by flow cytometry: comparison with fluorescence microscopy

The pre-B phenotype of childhood acute lymphoblastic leukemia, in which the mu immunoglobulin molecule is expressed in the cytoplasm of the blast cells, has been shown to have independent prognostic significance. Patients with this phenotype of the disease tend to have a poorer outcome on contemporary treatment regimens than do those with the other B-precursor phenotypes. For these clinical studies, the detection of the pre-B phenotype has depended upon fluorescent-microscope based techniques. A flow-cytometry based technique for the detection of the cytoplasmic mu immunoglobulin molecule is presented here and the results compared in detail with those of fluorescent microscopy. The results show that the two techniques are equivalent. The flow cytometry method has the advantage of a standardized control, is less labor intensive, and is observer-independent.

Phonological evaluation and remediation of speech deviations of a child with a repaired cleft palate: a case study

Phonological evaluation of the speech of a 5-year-old boy with a repaired cleft palate identified the prevalence of the following phonological patterns: singleton obstruent omission (both prevocalic and postvocalic, but particularly prevocalic voiceless); velar deviations (omissions and fronting); cluster reduction and cluster deletion; stridency deletion (omissions and stopping); liquid deviations (omissions, gliding, stopping, nasalizing, and vowelizing); and glottal replacement. The basic aspects of an individually designed facilitative remediation program based on the subject's phonological system are presented, and the results are discussed.

Evaluation of activated charcoal-sorbitol suspension as an antidote

Studies in rats were performed to evaluate the effect of sorbitol on the antidotal efficacy of activated charcoal against four test drugs and to investigate the influence of storage upon the antidotal effect of activated charcoal-sorbitol suspension. The antidotal potency of activated charcoal was not diminished by sorbitol solution 70% w/v. In fact, it was enhanced by the sorbitol solution, as indicated by greater decrease in peak tissue drug concentration, compared to the effect produced by activated charcoal in aqueous suspension. Furthermore, storage of activated charcoal in sorbitol for as long as 1 year did not reduce the antidotal-efficiency of the absorbent.

Saline cathartics and saline cathartics plus activated charcoal as antidotal treatments

The results of this experimental study indicate that Na2SO4 reduces the gastrointestinal absorption of aspirin, but not that of pentobarbital, chlorpheniramine, or chloroquine. Activated charcoal (AC) and the combination of AC + Na2SO4 were effective in reducing gastrointestinal absorption of all four test drugs. The combination treatment was more effective than AC treatment in reducing gastrointestinal absorption of aspirin, pentobarbital, and chloroquine. We believe that saline cathartics should not be used in lieu of AC for treatment of poison ingestions, and their routine use to treat poison ingestion should be reevaluated. On the other hand, saline cathartics may be used in conjunction with AC to enhance the antidotal effect of the adsorbent.

Velar stretch as a function of task

This study examined velar stretch in 20 young, normal adults during the production of /alpha/,/epsilon/, and /u/, and during blowing. Velar length was measured from cephalometric x-rays in two ways: (1) along the nasal surface of the velum and (2) along the velar midline. Results show no significant differences in velar stretch between males and females. Using nasal surface measures, there was significantly greater stretch for /u/ and for blowing than for /alpha/ and /epsilon/. For midline measures, the only differences which reached statistical significance were between blowing and /alpha/ or /epsilon/, which were not different from each other. Correlations between need ratio and percentage of stretch were significant as were correlations between percentage of velar stretch (nasal surface measure) and velar height. Comparisons of the two methods of measuring velar length are presented followed by a discussion concerning the significance of the findings.

Home parenteral nutrition

Home parenteral nutrition on a permanent basis can be done by patients who are reasonably intelligent and well motivated. The various aspects of such a scheme are described with reference to three patients in the Waikato area who have had extensive bowel resections. Use of A-V loop vein grafts avoids the necessity for indwelling plastic shunts or catheters.

Accidental paraquat poisonings

Three accidental deaths due to ingestion of paraquat are described. There is as yet no proven effective treatment once significant absorption has taken place. A short review of clinical features and recommended treatment is presented.

Cadmium levels in hair and other tissues during continuous cadmium intake

Rats that received cadmium 300 ppm in drinking water (average daily cadmium intake = 4.5 mg/rat) for 12 wk attained peak cadmium levels of 112, 34, and 19 mug/g in hair, liver, and kidney, respectively, at week 4. Rats that ingested cadmium 200 ppm (average daily cadmium intake = 3.6 mg/rat) for 13 wk attained peak cadmium levels of 29 mug/g in kidney at week 7, and 94 and 27 mug/g in hair and liver, respectively, at week 9. Despite continuous exposure to the heavy metal, tissue cadmium concentrations declined to steady-state levels of 24-33 mug/g in hair and 10-17 mug/g in liver and kidney. Histopathologic effects were not observed in liver or kidney. In contrast to cadmium in hair, blood cadmium levels, which remained consistently low (less than 0.04 mug/ml) throughout the study, did not correlate with changes in cadmium levels in liver and kidney.

Acute effects of morphine and chlorpromazine on the acquisition of shuttle box conditioned avoidance response

Morphine sulfate, 0.25-24.0 mg/kg, or chlorpromazine hydrochloride, 0.0625-4.0mg/kg were administered subcutaneously to naive rats 30 min prior to the start of massed-trials conditioned avoidance response (CAR) testing. The graded doses of both drugs were applied in each of three CAR task difficulty levels created by manipulation of the duration of conditioned and unconditioned stimuli, intertrial interval and shock intensity. Chlorpromazine, in a dose-related manner, caused a decrement in CAR acquisition in all tasks. Morphine, in comparison, produced a biphasic dose response. For a given task difficulty, low doses of morphine enhanced acquisition, whereas higher doses inhibited acquisition. With increasing task difficulty, relatively larger doses of morphine were required to inhibit or facilitate acquisition of CAR. These results emphasize the need to consider not only drug dosage levels, but also the interaction of task difficulty in the application of drugs in learning paradigms.

Delta-9-tetrahydrocannabinol, EEG and behavior:the importance of adaptation to the testing milieu

Delta-9-Tetrahydrocannabinol (delta-9-THC) in doses of 0.01, 0.05, 0.1, 0.5, and 1.0 mg/kg, i.v. was administered to adult rabbits previously adapted to the testing chamber. Additionally, a group of rabbits not adapted to any part of the testing regimen was administered 1.0 mg/kg delta-9-THC. Cortical and hippocampal electroencephalographs as well as postural and activity behaviors of the unrestrained animals were recorded. In the adapted rabbits, there were dose-related increased in cortical voltage output, disruption of hippocampal theta rhythm and cortical polyspike bursts. Behaviorally, there was a dose-related tendency for standing and exploration to decrease, and at 0.5 and 1.0 mg/lh, delta-9-THC produced sprawling. In the nonadapted rabbits, administration of 1.0 mg/kh of the drug caused EEG and behavioral stimulation followed by depression of both, The results suggest that the bahavioral actions of cannabinols are largely dependent upon the animal's existing state of arousal.