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Biomedical subjects

T Thompson

Publications and source records attributed to T Thompson.

At least 37 records · Page 2Linked to original sources
PubMed1988

Multimodality treatment of non-small cell lung cancer: response to cisplatin, VP-16, and 5-FU chemotherapy and to surgery and radiation therapy.

Twenty-one patients with unresectable non-small cell lung cancer (NSCLC), 11 with stage III M0, five with malignant pleural effusion, and five with a single resectable metastasis were treated with multimodality therapy. All received two to three cycles of preoperative chemotherapy with a new sequential combination of cisplatin (50 mg/m2 IV X 1) followed by 5-FU infusion (40 mg/m2/hr X 72) and etoposide (80 mg/m2/day X 3). Thirteen of 21 (62%) had a partial response, and three (14%) had a minor response to chemotherapy. Of the 19 who underwent surgical exploration, 17 were confirmed to have NSCLC. Ten patients with NSCLC and one with choriocarcinoma were rendered disease free by resection of the primary tumor and lymph nodes. Six received intra- and/or perioperative interstitial therapy with 125I and/or 192Ir. Another patient was treated with 32P. Postoperative external radiotherapy was administered in 15 patients, and adjuvant chemotherapy was administered in ten. This multimodality therapy was well tolerated, safe, and highly effective, resulting in excellent palliation even in patients with pleural effusion and metastasis. The most promising results were in unresectable stage III M0 with a partial response rate of 82% following neoadjuvant chemotherapy and a complete response rate of 73% after surgery. In this group, median survival has not yet been reached and will exceed 12 months.

Adult↗
PubMed1988

Chromatin structure of hormone-responsive Moloney murine leukemia virus proviruses that contain sequences from mouse mammary tumor virus.

The chromatin structure of chimeric Moloney murine leukemia viruses (M-MuLVs) containing a glucocorticoid response element (GRE) from mouse mammary tumor virus (MMTV) inserted into the long terminal repeat (LTR) was investigated. Nuclear run-on assays indicated that transcription from the chimeric proviruses was induced 2- to 4-fold by dexamethasone. The wild-type M-MuLV 5' LTR contained a DNase I hypersensitive (HS) site at the TATA sequences, as well as four sites in the enhancer region. The chimeric LTRs contained these sites, as well as three additional sites in the MMTV sequences. Two of the MMTV sites were present in the absence of hormone, while one was hormone-induced. In addition, internal MMTV sequences appeared protected from DNase I digestion in the absence of hormone, suggesting bound protein. Hormone treatment resulted in loss of the DNase I protection.

Base Sequence↗
PubMed1988

Stereotypic behavior of mentally retarded adults adjunctive to a positive reinforcement schedule.

Stereotypic behavior is one of the more common disturbed behaviors displayed by people who are developmentally disabled. This study evaluated the indirect effects on stereotypic frequency when the value of a concurrent fixed-interval reinforcement schedule for adaptive behavior was varied. Three profoundly mentally retarded adults performed a simple adaptive task reinforced under a fixed-interval schedule. The reinforcement schedule value was varied from fixed-interval 15 to 90, and 180 seconds after schedule control under each condition was demonstrated. The dependent measure was the frequency of stereotypic behavior. Stereotypic behavior increased in direct relation to the interval length. The theoretical and practical implications of treating stereotypies as an adjunctive behavior partially controlled by the reinforcement frequency for adaptive behaviors are discussed.

Adult↗
PubMed1988

Therapeutic options in IgA nephropathy.

IgA nephropathy (IgAN) is a common form of glomerulonephritis that leads to end-stage renal disease at variable rates in 20% to 30% of cases. A rational approach to therapy requires an understanding of pathogenetic mechanisms that are largely unknown. Several therapeutic approaches have been used, generally in uncontrolled trials, aimed at lowering levels of circulating immune complexes, affecting cellular immunity, or removing antigens through dietary restriction. Thus far, no clear-cut beneficial effects are evident. Alternative means of changing glomerular hemodynamics through prevention of harmful mediators await exploration.

Antigen-Antibody Complex↗
PubMed1988

Effects of buprenorphine, methadone and naloxone on acquisition of behavioral chains.

Buprenorphine, methadone and naloxone were administered to pigeons key pecking under a repeated acquisition procedure. Under this procedure subjects are required to emit a new sequence of responses each session to receive access to food. All three drugs reduced overall key pecking rates although naloxone's rate-reducing effect was limited to the highest dose (30 mg/kg). The dose-effect curves for overall key pecking rate under buprenorphine and methadone were similar though the effective dose range for buprenorphine appeared wider. Methadone increased percentage of total errors at the highest doses, but neither buprenorphine nor naloxone affected total error levels very much. Within-session errors were increased early in the session under high methadone doses. Low buprenorphine doses also showed some tendency to increase errors early in the session. Buprenorphine and methadone reduced the number of chains completed in a dose-dependent manner. Buprenorphine was also administered daily at the most behaviorally disruptive dose (10 mg/kg/day). Under this dosing schedule, the behavior-suppressing effects of buprenorphine returned to base-line levels within 4 days. Error rates were unaffected by daily buprenorphine administration.

Animals↗
PubMed1987

An animal model of the interpersonal communication of interoceptive (private) states.

Pigeons were taught to interact communicatively (i.e., exchange discriminative stimuli) based on 1 pigeon's internal state, which varied as a function of cocaine, pentobarbital, and saline administration. These performances generalized to untrained pharmacological agents (d-amphetamine and chlordiazepoxide) and were observed in the absence of aversive stimulation, deprivation, and unconditioned reinforcement. The training procedure used in this study appears similar to that by which humans learn to report on (tact) their internal environments and may be construed as a rudimentary animal model of the interpersonal communication of private events.

Animal Communication↗
PubMed1987

Interaction of methadone, reinforcement history, and variable-interval performance.

In the present study, we examined how a reinforcement schedule history that generated high or low rates of responding influenced the effects of acute (Experiment 1) and chronic (Experiment 2) methadone administration. Initially, key-peck responses of pigeons were maintained under a variable-interval 90-s schedule of food presentation, and a methadone dose-response curve was determined with doses of 0.6, 1.2, and 2.4 mg/kg. The pigeons were then exposed, for at least 40 sessions, to either a fixed-ratio 50 schedule or a differential-reinforcement-of-low-rate 10-s schedule, or were given continued exposure to the variable-interval schedule. The methadone dose-response curve was redetermined after all pigeons again were responding under the variable-interval schedule. The effects of two different daily methadone doses (9.0 and 12.0 mg/kg/day) and withdrawal precipitated by naloxone also were assessed. Experience with a fixed-ratio or differential reinforcement of low rate schedule did not result in significantly different response rates under the variable-interval schedule and, in general, the acute effects of methadone did not have differential effects correlated with schedule history. However, for 2 of 4 subjects the rate-decreasing effects of methadone on rates of key pecking were greater following a history of low-rate responding, suggesting a possible interaction between schedule history and effects of methadone. Daily methadone administration under the variable-interval schedule revealed that pigeons with experience under the differential reinforcement of low rate schedule developed more rapid and complete tolerance to the rate-decreasing effects of methadone. Three of the 4 subjects in this group showed rate increases above drug-free baselines during chronic methadone dosing. Pigeons with a history of fixed-ratio responding also developed tolerance to the rate-decreasing effects of methadone but without the subsequent rate increases seen by subjects with low-rate histories. No subjects with variable-interval histories showed complete recovery of drug-free baselines, suggesting that interpolated training under other schedules may attenuate the rate-altering effects of chronically administered drugs. Naloxone (1.0 mg/kg), administered during the chronic methadone phase, resulted in greater disruption of responding by pigeons with a history of low-rate responding, as compared to subjects in the other two groups.(ABSTRACT TRUNCATED AT 400 WORDS)

Animals↗
PubMed1987

Splenic hemangioma with thrombocytopenia in a newborn.

The case report of a newborn infant with a splenic hemangioendothelioma with the life-threatening complications of thrombocytopenia, anemia, and disseminated intravascular coagulation is presented together with a review of the literature. Removal of the tumor via splenectomy, despite the known risk of subsequent overwhelming sepsis due to encapsulated organisms in the young child, is the treatment of choice for splenic hemangiomas complicated by thrombocytopenia. The use of enhanced CT with delayed filling is a diagnostic tool in the workup of suspected hemangiomatous lesions.

Anemia, Neonatal↗
PubMed1986

Asynchronies of diphenhydramine plasma-performance relationships.

The relation between performance on driving-related tasks and plasma levels of diphenhydramine was studied in eight male volunteers over 24 hours following oral administration. DPH plasma concentrations rose to peak levels in 1.5-2.5 hours varying with dose, declining to a nearly constant level by 12-24 hours. For all behavioral measures, the shape of performance curves over time was similar to that of plasma, reaching maximum decrements in 1-4 hours. The relation between plasma levels and performance was asynchronous varying with behavioral measure and dose. The use of plasma DPH values to predict performance decrements is limited due to the bivalued nature of these relationships in time. Nonetheless, it would appear that if DPH is administered in the therapeutic dosage range at the intervals typically recommended for cold symptoms and allergies, it appears some aspects of human performance may be impaired.

Administration, Oral↗
PubMed1986

Effects of imipramine on responding reduced by methadone.

Interactions between methadone and acute and chronic imipramine were studied in pigeons key pecking under a multiple variable interval 15-sec variable interval 150-sec schedule of food presentation. Both drugs decreased response rates at the highest doses. The VI 15-sec schedule was slightly more sensitive to acute drug administration than was the variable interval 150-sec schedule. Acute combinations of the two drugs neither ameliorated nor exacerbated the effects of either drug alone. Chronic imipramine alone had no lasting effect on responding. Unlike acute combinations, chronic imipramine lessened the rate reducing effect of methadone.

Animals↗
PubMed1986

Structural similarity between the lepidoptera- and diptera-specific insecticidal endotoxin genes of Bacillus thuringiensis subsp. "kurstaki" and "israelensis".

A gene from Bacillus thuringiensis subsp. "israelensis" was cloned from the large plasmids of this subspecies and was shown to code for a mosquitocidal polypeptide. The gene could be expressed in either Escherichia coli, Bacillus subtilis, or B. thuringiensis subsp. "israelensis" to produce the larvicidal activity. Similarly, a Lepidoptera-specific toxin gene from B. thuringiensis subsp. "kurstaki" was also cloned and expressed in E. coli and B. subtilis. Both cloned genes were sequenced and subjected to computer analysis. A long open translational reading frame coded for the B. thuringiensis subsp. "kurstaki" gene product. However, the B. thuringiensis subsp. "israelensis" clone was composed of two adjacent open reading frames oriented as if they were in a transcriptional operon. The products of the cloned genes retained their specificity for either Lepidoptera or Diptera. The control regions immediately preceding the toxin genes of both B. thuringiensis subspecies showed considerable DNA homology, most likely because both toxins are expressed only during sporulation. In addition, the deduced amino acid sequences from the two contiguous B. thuringiensis subsp. "israelensis" genes bore a striking resemblance to the deduced amino acid sequence from the single larger B. thuringiensis subsp. "kurstaki" gene, as if these two arrangements were evolutionarily related.

Amino Acid Sequence↗